Ceftaroline fosamil (Teflaro), introduced to the US market in October 2010, is the first beta-lactam agent with clinically useful activity against methicillin-resistant Staphylococcus aureus (MRSA). Currently, it is approved by the US Food and Drug Administration (FDA) to treat acute bacterial skin and skin-structure infections and community-acquired bacterial pneumonia caused by susceptible microorganisms.

In an era of increasing drug resistance and limited numbers of antimicrobials in the drug-production pipeline, ceftaroline is a step forward in fulfilling the Infectious Diseases Society of America’s “10 × ’20 Initiative” to increase support for drug research and manufacturing, with the goal of producing 10 new antimicrobial drugs by the year 2020.¹ Ceftaroline was the first of several antibiotics to receive FDA approval in response to this initiative. It was followed by dalbavancin (May 2014), tedizolid phosphate (June 2014), oritavancin (August 2014), ceftolozane-tazobactam (December 2014), and ceftazidime-avibactam (February 2015). These antibiotic agents are aimed at treating infections caused by drug-resistant gram-positive and gram-negative microorganisms. It is important to understand and optimize the use of these new antibiotic agents in order to decrease the risk of emerging antibiotic resistance and superinfections (eg, Clostridium difficile infection) caused by antibiotic overuse or misuse.

This article provides an overview of ceftaroline’s mechanisms of action and resistance, spectrum of activity, pharmacokinetic properties, adverse effects, and current place in therapy.

AN ERA OF MULTIDRUG-RESISTANT MICROORGANISMS

Increasing rates of antimicrobial resistance threaten the efficacy of antimicrobial drugs in the daily practice of medicine. The World Health Organization has labeled antimicrobial resistance one of the three greatest threats to human health. Global efforts are under way to stimulate development of new antimicrobial agents and to decrease rates of antimicrobial resistance.

Staphylococcus aureus: A threat, even with vancomycin

Between 1998 and 2005, S aureus was one of the most common inpatient and outpatient isolates reported by clinical laboratories throughout the United States.²

Treatment of S aureus infection is complicated by a variety of resistance mechanisms that have evolved over time. In fact, the first resistant isolate of S aureus emerged not long after penicillin’s debut into clinical practice, and now the majority of strains are resistant to penicillin.

Methicillin was designed to overcome this beta-lactamase resistance and became the treatment of choice for penicillin-resistant S aureus isolates. However, MRSA isolates soon emerged because of the organism’s acquisition of penicillin-binding protein PBP2a via the mecA gene, leading to decreased binding affinity of methicillin.³

Since then, several agents active against MRSA (vancomycin, daptomycin, linezolid, tigecycline) have been introduced and continue to be widely used. While vancomycin is considered the first-line option for a variety of MRSA infections, its use has been threatened because of the emergence of vancomycin-intermediate-resistant S aureus (VISA), S aureus strains displaying vancomycin heteroresistance (hVISA), and vancomycin-resistant S aureus (VRSA) strains.⁴

VISA and hVISA isolates emerged through sequential mutations that lead to autolytic activity and cell-wall thickening. In contrast, the mechanism of resistance in VRSA is by acquisition of the vanA resistance gene, which alters the binding site of vancomycin from d-alanine-d-alanine to d-alanine-d-lactate.⁵

Streptococcus pneumoniae resistance: A continuing problem

The prevalence of drug resistance in S pneumoniae has risen since the late 1990s. A 2013 report from the SENTRY Antimicrobial Surveillance Program stated that almost 20% of S pneumoniae isolates were resistant to amoxicillin-clavulanate, and similar trends have been observed for penicillin (14.8%) and ceftriaxone (11.7%).⁶

S pneumoniae resistance is acquired through modifications of the penicillin-binding proteins, namely PBP1a, PBP2b, PBP2x, and, less frequently, PBP2a. These modifications lead to decreased binding affinity for most beta-lactams.⁷

Clinical impact of multidrug-resistant S aureus and S pneumoniae

In 2011, the US Centers for Disease Control and Prevention reported an estimated 80,000 severe MRSA infections and 11,000 MRSA-related deaths in the United States.⁸ In the same report, drug-resistant S pneumoniae was estimated to be responsible for almost 1.2 million illnesses and 7,000 deaths per year, leading to upwards of $96 million in related medical costs.

While invasive drug-resistant S pneumoniae infections usually affect patients at the extremes of age (under age 5 and over age 65), they have had a serious impact on patients of all ages.⁸

In light of the increasing prevalence of multidrug-resistant organisms, newer antimicrobial agents with novel mechanisms of action are needed.

CEFTAROLINE: A BETA-LACTAM WITH ANTI-MRSA ACTIVITY

The cephalosporins, a class of beta-lactam antibiotics, were originally derived from the fungus Cephalosporium (now called Acremonium). There are now many agents in this class, each containing a nucleus consisting of a beta-lactam ring fused to a six-member dihydrothiazine ring, and two side chains that can be modified to affect antibacterial activity and pharmacokinetic properties.

Cephalosporins are typically categorized into “generations.” With some exceptions, the first- and second-generation agents have good activity against gram-positive microorganisms, including methicillin-susceptible S aureus—but not against MRSA. The third- and fourth-generation cephalosporins have better gram-negative activity, with many agents having activity against the gram-negative bacterium Pseudomonas aeruginosa.

Enterococcal isolates are intrinsically resistant to cephalosporins. Additionally, cephalosporins are not active against anaerobic bacteria, except for a subset of structurally unique second-generation cephalosporins, ie, cefotetan and cefoxitin.

Ceftaroline was synthesized with specific manipulations of the side chains to provide enhanced activity against MRSA and multidrug-resistant S pneumoniae isolates, making it the first available beta-lactam with this ability.

Mechanism of action

Ceftaroline binds to penicillin-binding proteins, inhibiting transpeptidation. This interaction blocks the final stage of peptidoglycan synthesis and inhibits bacterial cell wall formation, ultimately leading to cellular autolysis and microorganism death. Ceftaroline binds with high affinity to PBP2a and PBP2x, expanding its activity to encompass MRSA and penicillin-resistant S pneumoniae isolates.⁹

Spectrum of activity

Ceftaroline has in vitro activity against many gram-positive and gram-negative bacteria,^10–13 including (Table 1):

• Methicillin-susceptible and methicillin-resistant staphylococci
• VISA, VRSA, and hVISA
• Daptomycin-nonsusceptible S aureus
• Streptococcal species, including penicillin-resistant S pneumoniae
• Enterobacteriaceae, including Klebsiella pneumoniae, Klebsiella oxytoca, Escherichia coli, Citrobacter koseri, Citrobacter freundii, Enterobacter cloacae, Enterobacter aerogenes, Moraxella catarrhalis, Morganella morganii, and Proteus mirabilis.

Of note, ceftaroline is not active against Pseudomonas species, Enterococcus species, or Bacteroides fragilis. In addition, it is not active against the “atypical” respiratory pathogens Mycoplasma pneumoniae, Chlamydophila pneumoniae, and Legionella pneumophila.

Ceftaroline resistance

Gram-negative organisms appear to develop resistance to ceftaroline at rates similar to those observed with the other oxyimino-cephalosporins (eg, ceftriaxone). Ceftaroline is inactive against gram-negative organisms producing extended-spectrum beta-lactamases, including K pneumoniae carbapenemase and metallo-beta-lactamases.¹⁴ In addition, it induces the expression of AmpC beta-lactamases.

Although currently uncommon, resistance to ceftaroline has also been reported in S aureus strains.¹⁵ The mechanism of resistance is decreased binding affinity for PBP2a due to amino acid substitutions on the nonpenicillin-binding domains.¹⁵

Pharmacokinetic profile

An understanding of pharmacokinetics is key in optimizing the dose of antimicrobials so that the drugs are used most effectively and pathogens do not develop resistance to them.

Ceftaroline fosamil is a prodrug that, upon intravenous administration, is rapidly converted by phosphatase enzymes to its active moiety, ceftaroline. Its pharmacokinetic profile is summarized in Table 2.^16,17 Its volume of distribution is similar to that of the fourth-generation cephalosporin cefepime.

Ceftaroline is then hydrolyzed into its inactive metabolite, ceftaroline M-1. It undergoes little hepatic metabolism and lacks properties to make it a substrate, inhibitor, or inducer of the CYP450 enzyme system and therefore is not likely to cause notable CYP450-related drug-drug interactions.

Like most other beta-lactams, ceftaroline is primarily excreted by the kidneys. Furthermore, an estimated 21% of a dose is eliminated with each intermittent hemodialysis session. Therefore, renal and intermittent hemodialysis dose adjustments are necessary. The estimated elimination half-life is 2.6 hours, necessitating dosing two to three times daily, depending on the indication and infectious inoculum.

Ceftaroline dosing

Ceftaroline is available only in a parenteral preparation and is typically given at a dose of 600 mg every 12 hours.¹⁰ The intravenous infusion is given over 1 hour.

The current stability data require reconstituted ceftaroline to be used within 6 hours at room temperature and within 24 hours if refrigerated.¹⁰

Ceftaroline requires dosing adjustments for patients with renal insufficiency. Per the manufacturer, renal dosing adjustments are based on the creatinine clearance rate, as estimated by the Cockroft-Gault formula:

• Creatinine clearance > 50 mL/min: no dosage adjustment necessary
• Creatinine clearance > 30 to ≤ 50 mL/min: give 400 mg every 12 hours
• Creatinine clearance ≥ 15 to ≤ 30 mL/min: give 300 mg every 12 hours
• Creatinine clearance < 15 mL/min or on intermittent dialysis: give 200 mg every 12 hours.

Ongoing clinical trials are investigating a higher-dosing strategy of 600 mg every 8 hours for patients with community-acquired bacterial pneumonia at risk of MRSA bacteremia.¹⁸

CLINICAL TRIALS LEADING TO CEFTAROLINE’S APPROVAL

Ceftaroline was approved for the treatment of community-acquired bacterial pneumonia and acute bacterial skin and skin-structure infections due to susceptible pathogens on the basis of phase 3 comparator trials.

Community-acquired bacterial pneumonia: The FOCUS 1 and 2 trials

The efficacy and safety of ceftaroline in the treatment of community-acquired bacterial pneumonia was studied in two randomized, double-blind, noninferiority trials, known as Ceftaroline Community-acquired Pneumonia vs Ceftriaxone (FOCUS) 1 and FOCUS 2.^19,20

Patients were adults and not critically ill, as was reflected by their being in Pneumonia Outcomes Research Team (PORT) risk class III or IV (with class V indicating the highest risk of death). Therefore, the results may not be completely applicable to critically ill patients or those not admitted to the hospital. Of note, patients were excluded from the trials if they had infections known or thought to be due to MRSA or to atypical organisms.²¹ Baseline characteristics and patient demographics were similar between study groups in both trials.

A bacterial pathogen was identified in 26.1% of the patients included in the modified intent-to-treat analysis of the pooled data of the trials; the most common pathogens were S pneumoniae, methicillin-sensitive S aureus, Haemophilus influenzae, K pneumoniae, and E coli.²¹

Treatment. Patients received either ceftaroline 600 mg every 12 hours (or a lower dose based on renal function) or ceftriaxone 1 g every 24 hours. In addition, in the FOCUS 1 trial, patients in both treatment groups received clarithromycin 500 mg every 12 hours for the first day.¹⁹

Results. In both trials and in the integrated analysis, ceftaroline was noninferior to ceftriaxone (Table 3).²² In the integrated analysis of both trials, compared with the ceftriaxone group, the ceftaroline group had a higher clinical cure rate among patients classified as PORT risk class III (86.8% vs 79.2%, weighted treatment difference 12.6%, 95% confidence interval [CI] 1.3–13.8) and among patients who had not received prior antibiotic treatment (85.5% vs 74.9%, weighted treatment difference 11.2%, 95% CI 4.5–18.0).²¹

Acute bacterial skin and skin-structure infections: The CANVAS 1 and 2 trials

The efficacy and safety of ceftaroline in the treatment of complicated acute bacterial skin and skin-structure infections was studied in two randomized, double-blind trials: Ceftaroline Versus Vancomycin in Skin and Skin Structure Infections (CANVAS) 1 and CANVAS 2.^23,24

Patients. Adult patients with a diagnosis of community-acquired skin and skin-structure infections warranting at least 5 days of intravenous antimicrobial therapy were included in the trials. Important protocol exclusions were patients with diabetic foot ulcers, decubitus ulcers, burns, ulcers associated with peripheral vascular disease accompanied by osteomyelitis, and suspected P aeruginosa infections.²⁵ This limits the external validity of ceftaroline use in the aforementioned excluded patient populations.

Patients in each treatment group of the trials had similar demographic characteristics. The most common infections were cellulitis, major abscess requiring surgical intervention, wound infection, and infected ulcer. Bacteremia was present in 4.2% of patients in the ceftaroline group and in 3.8% of patients in the vancomycin-aztreonam group. The most common pathogen was S aureus. Methicillin resistance was present in 40% of the ceftaroline group and 34% of the control group.

Treatment. Patients received either ceftaroline 600 mg every 12 hours or the combination of vancomycin 1 g plus aztreonam 1 g given 12 hours, for 5 to 14 days.

Results. As assessed at a “test-of-cure” visit 8 to 15 days after the last dose of study medication, the efficacy of ceftaroline was similar to that of vancomycin-aztreonam, meeting the set noninferiority goal (Table 4).²⁵ Moreover, if assessed on day 2 or 3 (a new end point recommended by the FDA), the rate of cessation of erythema spread and absence of fever was higher in the ceftaroline group than in the vancomycin-aztreonam group.²⁶ However, this end point was not in the original trial protocol.

CEFTAROLINE FOR OTHER INDICATIONS

As noted, ceftaroline has been approved for treating community-acquired bacterial pneumonia and acute bacterial skin and skin-structure infections. In addition, it has been used in several studies in animals, and case reports of non-FDA approved indications including endocarditis and osteomyelitis have been published. Clinical trials are evaluating its use in pediatric patients, as well as for community-acquired bacterial pneumonia with risk for MRSA and for MRSA bacteremia.

Endocarditis

Animal studies have demonstrated ceftaroline to have bactericidal activity against MRSA and hVISA in endocarditis.²⁷

A few case series have been published describing ceftaroline’s use as salvage therapy for persistent MRSA bacteremia and endocarditis. For example, Ho et al²⁸ reported using it in three patients who had endocarditis as a source of their persistent bacteremia. All three patients had resolution of their MRSA bloodstream infection following ceftaroline therapy. The dosage was 600 mg every 8 hours, which is higher than in the manufacturer’s prescribing information.

Lin et al²⁹ reported using ceftaroline in five patients with either possible or probable endocarditis. Three of the five patients had clinical cure as defined by resolution or improvement of all signs and symptoms of infection, and not requiring further antimicrobial therapy.²⁹

More data from clinical trials would be beneficial in defining ceftaroline’s role in treating endocarditis caused by susceptible microorganisms.

Osteomyelitis

In animal studies of osteomyelitis, ceftaroline exhibited activity against MRSA in infected bone and joint fluid. Compared with vancomycin and linezolid, ceftaroline was associated with more significant decreases in bacterial load in the infected joint fluid, bone marrow, and bone.³⁰

Lin et al²⁹ gave ceftaroline to two patients with bone and joint infections, both of whom had received other therapies that had failed. The doses of ceftaroline were higher than those recommended in the prescribing information; clinical cure was noted in both cases following the switch.

These data come from case series, and more study of ceftaroline’s role in the treatment of osteomyelitis infections is warranted.

Meningitis

The use of ceftaroline in meningitis has been studied in rabbits. While ceftaroline penetrated into the cerebrospinal fluid in only negligible amounts in healthy rabbits (3% penetration), its penetration improved to 15% in animals with inflamed meninges. Ceftaroline cerebrospinal fluid levels in inflamed meninges were sufficient to provide bactericidal activity against penicillin-sensitive and resistant S pneumoniae strains as well as K pneumoniae and E coli strains.^31,32

REPORTED ADVERSE EFFECTS OF CEFTAROLINE

Overall, ceftaroline was well tolerated in clinical trials, and its safety profile was similar to those of the comparator agents (ceftriaxone and vancomycin-aztreonam).

As with the other cephalosporins, hypersensitivity reactions have been reported with ceftaroline. In the clinical trials, 3% of patients developed a rash with ceftaroline.^33,34 Patients with a history of beta-lactam allergy were excluded from the trials, so the rate of cross-reactivity with penicillins and with other cephalosporins is unknown.

In the phase 3 clinical trials, gastrointestinal side effects including diarrhea (5%), nausea (4%), and vomiting (2%) were reported with ceftaroline. C difficile-associated diarrhea has also been reported.³³

As with other cephalosporins, ceftaroline can cause a false-positive result on the Coombs test. Approximately 11% of ceftaroline-treated patients in phase 3 clinical trials had a positive Coombs test, but hemolytic anemia did not occur in any patients.^33,34

Discontinuation of ceftaroline due to an adverse reaction was reported in 2.7% of patients receiving the drug during phase 3 trials, compared with 3.7% with comparator agents.

WHEN SHOULD CEFTAROLINE BE USED IN DAILY PRACTICE?

Ceftaroline has been shown to be at least as effective as ceftriaxone in treating community-acquired bacterial pneumonia, and at least as effective as vancomycin-aztreonam in treating acute bacterial skin and skin-structure infections. The 2014 Infectious Diseases Society of America’s guidelines for the diagnosis and management of skin and soft-tissue infections recommend ceftaroline as an option for empiric therapy for purulent skin and soft-tissue infections.³⁵

The guidelines on community-acquired pneumonia have not been updated since 2007, which was before ceftaroline was approved. However, these guidelines are currently undergoing revision and may provide insight on ceftaroline’s place in the treatment of community-acquired bacterial pneumonia.³⁶

Currently, ceftaroline’s routine use for these indications should be balanced by its higher cost ($150 for a 600-mg dose) compared with ceftriaxone ($5 for a 1-g dose) or vancomycin ($25 for a 1-g dose). The drug’s in vitro activity against drug-resistant pneumococci and S aureus, including MRSA, hVISA, and VISA may help fill an unmet need or provide a safer and more tolerable alternative to currently available therapies.

However, ceftaroline’s lack of activity against P aeruginosa and carbapenem-resistant Enterobacteriaceae does not meet the public health threat needs stemming from these multidrug-resistant microorganisms. Ongoing clinical trials in patients with more serious MRSA infections will provide important information about ceftaroline’s role as an anti-MRSA agent.

While the discovery of antimicrobials has had one of the greatest impacts on medicine, continued antibiotic use is threatened by the emergence of drug-resistant pathogens. Therefore, it is as important as ever to be good stewards of our currently available antimicrobials. Developing usage and dosing criteria for antimicrobials based on available data and literature is a step forward in optimizing the use of antibiotics—a precious medical resource.

Ceftaroline fosamil (Teflaro), introduced to the US market in October 2010, is the first beta-lactam agent with clinically useful activity against methicillin-resistant Staphylococcus aureus (MRSA). Currently, it is approved by the US Food and Drug Administration (FDA) to treat acute bacterial skin and skin-structure infections and community-acquired bacterial pneumonia caused by susceptible microorganisms.

In an era of increasing drug resistance and limited numbers of antimicrobials in the drug-production pipeline, ceftaroline is a step forward in fulfilling the Infectious Diseases Society of America’s “10 × ’20 Initiative” to increase support for drug research and manufacturing, with the goal of producing 10 new antimicrobial drugs by the year 2020.¹ Ceftaroline was the first of several antibiotics to receive FDA approval in response to this initiative. It was followed by dalbavancin (May 2014), tedizolid phosphate (June 2014), oritavancin (August 2014), ceftolozane-tazobactam (December 2014), and ceftazidime-avibactam (February 2015). These antibiotic agents are aimed at treating infections caused by drug-resistant gram-positive and gram-negative microorganisms. It is important to understand and optimize the use of these new antibiotic agents in order to decrease the risk of emerging antibiotic resistance and superinfections (eg, Clostridium difficile infection) caused by antibiotic overuse or misuse.

This article provides an overview of ceftaroline’s mechanisms of action and resistance, spectrum of activity, pharmacokinetic properties, adverse effects, and current place in therapy.

AN ERA OF MULTIDRUG-RESISTANT MICROORGANISMS

Increasing rates of antimicrobial resistance threaten the efficacy of antimicrobial drugs in the daily practice of medicine. The World Health Organization has labeled antimicrobial resistance one of the three greatest threats to human health. Global efforts are under way to stimulate development of new antimicrobial agents and to decrease rates of antimicrobial resistance.

Staphylococcus aureus: A threat, even with vancomycin

Between 1998 and 2005, S aureus was one of the most common inpatient and outpatient isolates reported by clinical laboratories throughout the United States.²

Treatment of S aureus infection is complicated by a variety of resistance mechanisms that have evolved over time. In fact, the first resistant isolate of S aureus emerged not long after penicillin’s debut into clinical practice, and now the majority of strains are resistant to penicillin.

Methicillin was designed to overcome this beta-lactamase resistance and became the treatment of choice for penicillin-resistant S aureus isolates. However, MRSA isolates soon emerged because of the organism’s acquisition of penicillin-binding protein PBP2a via the mecA gene, leading to decreased binding affinity of methicillin.³

Since then, several agents active against MRSA (vancomycin, daptomycin, linezolid, tigecycline) have been introduced and continue to be widely used. While vancomycin is considered the first-line option for a variety of MRSA infections, its use has been threatened because of the emergence of vancomycin-intermediate-resistant S aureus (VISA), S aureus strains displaying vancomycin heteroresistance (hVISA), and vancomycin-resistant S aureus (VRSA) strains.⁴

VISA and hVISA isolates emerged through sequential mutations that lead to autolytic activity and cell-wall thickening. In contrast, the mechanism of resistance in VRSA is by acquisition of the vanA resistance gene, which alters the binding site of vancomycin from d-alanine-d-alanine to d-alanine-d-lactate.⁵

Streptococcus pneumoniae resistance: A continuing problem

The prevalence of drug resistance in S pneumoniae has risen since the late 1990s. A 2013 report from the SENTRY Antimicrobial Surveillance Program stated that almost 20% of S pneumoniae isolates were resistant to amoxicillin-clavulanate, and similar trends have been observed for penicillin (14.8%) and ceftriaxone (11.7%).⁶

S pneumoniae resistance is acquired through modifications of the penicillin-binding proteins, namely PBP1a, PBP2b, PBP2x, and, less frequently, PBP2a. These modifications lead to decreased binding affinity for most beta-lactams.⁷

Clinical impact of multidrug-resistant S aureus and S pneumoniae

In 2011, the US Centers for Disease Control and Prevention reported an estimated 80,000 severe MRSA infections and 11,000 MRSA-related deaths in the United States.⁸ In the same report, drug-resistant S pneumoniae was estimated to be responsible for almost 1.2 million illnesses and 7,000 deaths per year, leading to upwards of $96 million in related medical costs.

While invasive drug-resistant S pneumoniae infections usually affect patients at the extremes of age (under age 5 and over age 65), they have had a serious impact on patients of all ages.⁸

In light of the increasing prevalence of multidrug-resistant organisms, newer antimicrobial agents with novel mechanisms of action are needed.

CEFTAROLINE: A BETA-LACTAM WITH ANTI-MRSA ACTIVITY

The cephalosporins, a class of beta-lactam antibiotics, were originally derived from the fungus Cephalosporium (now called Acremonium). There are now many agents in this class, each containing a nucleus consisting of a beta-lactam ring fused to a six-member dihydrothiazine ring, and two side chains that can be modified to affect antibacterial activity and pharmacokinetic properties.

Cephalosporins are typically categorized into “generations.” With some exceptions, the first- and second-generation agents have good activity against gram-positive microorganisms, including methicillin-susceptible S aureus—but not against MRSA. The third- and fourth-generation cephalosporins have better gram-negative activity, with many agents having activity against the gram-negative bacterium Pseudomonas aeruginosa.

Enterococcal isolates are intrinsically resistant to cephalosporins. Additionally, cephalosporins are not active against anaerobic bacteria, except for a subset of structurally unique second-generation cephalosporins, ie, cefotetan and cefoxitin.

Ceftaroline was synthesized with specific manipulations of the side chains to provide enhanced activity against MRSA and multidrug-resistant S pneumoniae isolates, making it the first available beta-lactam with this ability.

Mechanism of action

Ceftaroline binds to penicillin-binding proteins, inhibiting transpeptidation. This interaction blocks the final stage of peptidoglycan synthesis and inhibits bacterial cell wall formation, ultimately leading to cellular autolysis and microorganism death. Ceftaroline binds with high affinity to PBP2a and PBP2x, expanding its activity to encompass MRSA and penicillin-resistant S pneumoniae isolates.⁹

Spectrum of activity

Ceftaroline has in vitro activity against many gram-positive and gram-negative bacteria,^10–13 including (Table 1):

• Methicillin-susceptible and methicillin-resistant staphylococci
• VISA, VRSA, and hVISA
• Daptomycin-nonsusceptible S aureus
• Streptococcal species, including penicillin-resistant S pneumoniae
• Enterobacteriaceae, including Klebsiella pneumoniae, Klebsiella oxytoca, Escherichia coli, Citrobacter koseri, Citrobacter freundii, Enterobacter cloacae, Enterobacter aerogenes, Moraxella catarrhalis, Morganella morganii, and Proteus mirabilis.

Of note, ceftaroline is not active against Pseudomonas species, Enterococcus species, or Bacteroides fragilis. In addition, it is not active against the “atypical” respiratory pathogens Mycoplasma pneumoniae, Chlamydophila pneumoniae, and Legionella pneumophila.

Ceftaroline resistance

Gram-negative organisms appear to develop resistance to ceftaroline at rates similar to those observed with the other oxyimino-cephalosporins (eg, ceftriaxone). Ceftaroline is inactive against gram-negative organisms producing extended-spectrum beta-lactamases, including K pneumoniae carbapenemase and metallo-beta-lactamases.¹⁴ In addition, it induces the expression of AmpC beta-lactamases.

Although currently uncommon, resistance to ceftaroline has also been reported in S aureus strains.¹⁵ The mechanism of resistance is decreased binding affinity for PBP2a due to amino acid substitutions on the nonpenicillin-binding domains.¹⁵

Pharmacokinetic profile

An understanding of pharmacokinetics is key in optimizing the dose of antimicrobials so that the drugs are used most effectively and pathogens do not develop resistance to them.

Ceftaroline fosamil is a prodrug that, upon intravenous administration, is rapidly converted by phosphatase enzymes to its active moiety, ceftaroline. Its pharmacokinetic profile is summarized in Table 2.^16,17 Its volume of distribution is similar to that of the fourth-generation cephalosporin cefepime.

Ceftaroline is then hydrolyzed into its inactive metabolite, ceftaroline M-1. It undergoes little hepatic metabolism and lacks properties to make it a substrate, inhibitor, or inducer of the CYP450 enzyme system and therefore is not likely to cause notable CYP450-related drug-drug interactions.

Like most other beta-lactams, ceftaroline is primarily excreted by the kidneys. Furthermore, an estimated 21% of a dose is eliminated with each intermittent hemodialysis session. Therefore, renal and intermittent hemodialysis dose adjustments are necessary. The estimated elimination half-life is 2.6 hours, necessitating dosing two to three times daily, depending on the indication and infectious inoculum.

Ceftaroline dosing

Ceftaroline is available only in a parenteral preparation and is typically given at a dose of 600 mg every 12 hours.¹⁰ The intravenous infusion is given over 1 hour.

The current stability data require reconstituted ceftaroline to be used within 6 hours at room temperature and within 24 hours if refrigerated.¹⁰

Ceftaroline requires dosing adjustments for patients with renal insufficiency. Per the manufacturer, renal dosing adjustments are based on the creatinine clearance rate, as estimated by the Cockroft-Gault formula:

• Creatinine clearance > 50 mL/min: no dosage adjustment necessary
• Creatinine clearance > 30 to ≤ 50 mL/min: give 400 mg every 12 hours
• Creatinine clearance ≥ 15 to ≤ 30 mL/min: give 300 mg every 12 hours
• Creatinine clearance < 15 mL/min or on intermittent dialysis: give 200 mg every 12 hours.

Ongoing clinical trials are investigating a higher-dosing strategy of 600 mg every 8 hours for patients with community-acquired bacterial pneumonia at risk of MRSA bacteremia.¹⁸

CLINICAL TRIALS LEADING TO CEFTAROLINE’S APPROVAL

Ceftaroline was approved for the treatment of community-acquired bacterial pneumonia and acute bacterial skin and skin-structure infections due to susceptible pathogens on the basis of phase 3 comparator trials.

Community-acquired bacterial pneumonia: The FOCUS 1 and 2 trials

The efficacy and safety of ceftaroline in the treatment of community-acquired bacterial pneumonia was studied in two randomized, double-blind, noninferiority trials, known as Ceftaroline Community-acquired Pneumonia vs Ceftriaxone (FOCUS) 1 and FOCUS 2.^19,20

Patients were adults and not critically ill, as was reflected by their being in Pneumonia Outcomes Research Team (PORT) risk class III or IV (with class V indicating the highest risk of death). Therefore, the results may not be completely applicable to critically ill patients or those not admitted to the hospital. Of note, patients were excluded from the trials if they had infections known or thought to be due to MRSA or to atypical organisms.²¹ Baseline characteristics and patient demographics were similar between study groups in both trials.

A bacterial pathogen was identified in 26.1% of the patients included in the modified intent-to-treat analysis of the pooled data of the trials; the most common pathogens were S pneumoniae, methicillin-sensitive S aureus, Haemophilus influenzae, K pneumoniae, and E coli.²¹

Treatment. Patients received either ceftaroline 600 mg every 12 hours (or a lower dose based on renal function) or ceftriaxone 1 g every 24 hours. In addition, in the FOCUS 1 trial, patients in both treatment groups received clarithromycin 500 mg every 12 hours for the first day.¹⁹

Results. In both trials and in the integrated analysis, ceftaroline was noninferior to ceftriaxone (Table 3).²² In the integrated analysis of both trials, compared with the ceftriaxone group, the ceftaroline group had a higher clinical cure rate among patients classified as PORT risk class III (86.8% vs 79.2%, weighted treatment difference 12.6%, 95% confidence interval [CI] 1.3–13.8) and among patients who had not received prior antibiotic treatment (85.5% vs 74.9%, weighted treatment difference 11.2%, 95% CI 4.5–18.0).²¹

Acute bacterial skin and skin-structure infections: The CANVAS 1 and 2 trials

The efficacy and safety of ceftaroline in the treatment of complicated acute bacterial skin and skin-structure infections was studied in two randomized, double-blind trials: Ceftaroline Versus Vancomycin in Skin and Skin Structure Infections (CANVAS) 1 and CANVAS 2.^23,24

Patients. Adult patients with a diagnosis of community-acquired skin and skin-structure infections warranting at least 5 days of intravenous antimicrobial therapy were included in the trials. Important protocol exclusions were patients with diabetic foot ulcers, decubitus ulcers, burns, ulcers associated with peripheral vascular disease accompanied by osteomyelitis, and suspected P aeruginosa infections.²⁵ This limits the external validity of ceftaroline use in the aforementioned excluded patient populations.

Patients in each treatment group of the trials had similar demographic characteristics. The most common infections were cellulitis, major abscess requiring surgical intervention, wound infection, and infected ulcer. Bacteremia was present in 4.2% of patients in the ceftaroline group and in 3.8% of patients in the vancomycin-aztreonam group. The most common pathogen was S aureus. Methicillin resistance was present in 40% of the ceftaroline group and 34% of the control group.

Treatment. Patients received either ceftaroline 600 mg every 12 hours or the combination of vancomycin 1 g plus aztreonam 1 g given 12 hours, for 5 to 14 days.

Results. As assessed at a “test-of-cure” visit 8 to 15 days after the last dose of study medication, the efficacy of ceftaroline was similar to that of vancomycin-aztreonam, meeting the set noninferiority goal (Table 4).²⁵ Moreover, if assessed on day 2 or 3 (a new end point recommended by the FDA), the rate of cessation of erythema spread and absence of fever was higher in the ceftaroline group than in the vancomycin-aztreonam group.²⁶ However, this end point was not in the original trial protocol.

CEFTAROLINE FOR OTHER INDICATIONS

As noted, ceftaroline has been approved for treating community-acquired bacterial pneumonia and acute bacterial skin and skin-structure infections. In addition, it has been used in several studies in animals, and case reports of non-FDA approved indications including endocarditis and osteomyelitis have been published. Clinical trials are evaluating its use in pediatric patients, as well as for community-acquired bacterial pneumonia with risk for MRSA and for MRSA bacteremia.

Endocarditis

Animal studies have demonstrated ceftaroline to have bactericidal activity against MRSA and hVISA in endocarditis.²⁷

A few case series have been published describing ceftaroline’s use as salvage therapy for persistent MRSA bacteremia and endocarditis. For example, Ho et al²⁸ reported using it in three patients who had endocarditis as a source of their persistent bacteremia. All three patients had resolution of their MRSA bloodstream infection following ceftaroline therapy. The dosage was 600 mg every 8 hours, which is higher than in the manufacturer’s prescribing information.

Lin et al²⁹ reported using ceftaroline in five patients with either possible or probable endocarditis. Three of the five patients had clinical cure as defined by resolution or improvement of all signs and symptoms of infection, and not requiring further antimicrobial therapy.²⁹

More data from clinical trials would be beneficial in defining ceftaroline’s role in treating endocarditis caused by susceptible microorganisms.

Osteomyelitis

In animal studies of osteomyelitis, ceftaroline exhibited activity against MRSA in infected bone and joint fluid. Compared with vancomycin and linezolid, ceftaroline was associated with more significant decreases in bacterial load in the infected joint fluid, bone marrow, and bone.³⁰

Lin et al²⁹ gave ceftaroline to two patients with bone and joint infections, both of whom had received other therapies that had failed. The doses of ceftaroline were higher than those recommended in the prescribing information; clinical cure was noted in both cases following the switch.

These data come from case series, and more study of ceftaroline’s role in the treatment of osteomyelitis infections is warranted.

Meningitis

The use of ceftaroline in meningitis has been studied in rabbits. While ceftaroline penetrated into the cerebrospinal fluid in only negligible amounts in healthy rabbits (3% penetration), its penetration improved to 15% in animals with inflamed meninges. Ceftaroline cerebrospinal fluid levels in inflamed meninges were sufficient to provide bactericidal activity against penicillin-sensitive and resistant S pneumoniae strains as well as K pneumoniae and E coli strains.^31,32

REPORTED ADVERSE EFFECTS OF CEFTAROLINE

Overall, ceftaroline was well tolerated in clinical trials, and its safety profile was similar to those of the comparator agents (ceftriaxone and vancomycin-aztreonam).

As with the other cephalosporins, hypersensitivity reactions have been reported with ceftaroline. In the clinical trials, 3% of patients developed a rash with ceftaroline.^33,34 Patients with a history of beta-lactam allergy were excluded from the trials, so the rate of cross-reactivity with penicillins and with other cephalosporins is unknown.

In the phase 3 clinical trials, gastrointestinal side effects including diarrhea (5%), nausea (4%), and vomiting (2%) were reported with ceftaroline. C difficile-associated diarrhea has also been reported.³³

As with other cephalosporins, ceftaroline can cause a false-positive result on the Coombs test. Approximately 11% of ceftaroline-treated patients in phase 3 clinical trials had a positive Coombs test, but hemolytic anemia did not occur in any patients.^33,34

Discontinuation of ceftaroline due to an adverse reaction was reported in 2.7% of patients receiving the drug during phase 3 trials, compared with 3.7% with comparator agents.

WHEN SHOULD CEFTAROLINE BE USED IN DAILY PRACTICE?

Ceftaroline has been shown to be at least as effective as ceftriaxone in treating community-acquired bacterial pneumonia, and at least as effective as vancomycin-aztreonam in treating acute bacterial skin and skin-structure infections. The 2014 Infectious Diseases Society of America’s guidelines for the diagnosis and management of skin and soft-tissue infections recommend ceftaroline as an option for empiric therapy for purulent skin and soft-tissue infections.³⁵

The guidelines on community-acquired pneumonia have not been updated since 2007, which was before ceftaroline was approved. However, these guidelines are currently undergoing revision and may provide insight on ceftaroline’s place in the treatment of community-acquired bacterial pneumonia.³⁶

Currently, ceftaroline’s routine use for these indications should be balanced by its higher cost ($150 for a 600-mg dose) compared with ceftriaxone ($5 for a 1-g dose) or vancomycin ($25 for a 1-g dose). The drug’s in vitro activity against drug-resistant pneumococci and S aureus, including MRSA, hVISA, and VISA may help fill an unmet need or provide a safer and more tolerable alternative to currently available therapies.

However, ceftaroline’s lack of activity against P aeruginosa and carbapenem-resistant Enterobacteriaceae does not meet the public health threat needs stemming from these multidrug-resistant microorganisms. Ongoing clinical trials in patients with more serious MRSA infections will provide important information about ceftaroline’s role as an anti-MRSA agent.

While the discovery of antimicrobials has had one of the greatest impacts on medicine, continued antibiotic use is threatened by the emergence of drug-resistant pathogens. Therefore, it is as important as ever to be good stewards of our currently available antimicrobials. Developing usage and dosing criteria for antimicrobials based on available data and literature is a step forward in optimizing the use of antibiotics—a precious medical resource.

Ceftaroline fosamil (Teflaro), introduced to the US market in October 2010, is the first beta-lactam agent with clinically useful activity against methicillin-resistant Staphylococcus aureus (MRSA). Currently, it is approved by the US Food and Drug Administration (FDA) to treat acute bacterial skin and skin-structure infections and community-acquired bacterial pneumonia caused by susceptible microorganisms.

In an era of increasing drug resistance and limited numbers of antimicrobials in the drug-production pipeline, ceftaroline is a step forward in fulfilling the Infectious Diseases Society of America’s “10 × ’20 Initiative” to increase support for drug research and manufacturing, with the goal of producing 10 new antimicrobial drugs by the year 2020.¹ Ceftaroline was the first of several antibiotics to receive FDA approval in response to this initiative. It was followed by dalbavancin (May 2014), tedizolid phosphate (June 2014), oritavancin (August 2014), ceftolozane-tazobactam (December 2014), and ceftazidime-avibactam (February 2015). These antibiotic agents are aimed at treating infections caused by drug-resistant gram-positive and gram-negative microorganisms. It is important to understand and optimize the use of these new antibiotic agents in order to decrease the risk of emerging antibiotic resistance and superinfections (eg, Clostridium difficile infection) caused by antibiotic overuse or misuse.

This article provides an overview of ceftaroline’s mechanisms of action and resistance, spectrum of activity, pharmacokinetic properties, adverse effects, and current place in therapy.

AN ERA OF MULTIDRUG-RESISTANT MICROORGANISMS

Increasing rates of antimicrobial resistance threaten the efficacy of antimicrobial drugs in the daily practice of medicine. The World Health Organization has labeled antimicrobial resistance one of the three greatest threats to human health. Global efforts are under way to stimulate development of new antimicrobial agents and to decrease rates of antimicrobial resistance.

Staphylococcus aureus: A threat, even with vancomycin

Between 1998 and 2005, S aureus was one of the most common inpatient and outpatient isolates reported by clinical laboratories throughout the United States.²

Treatment of S aureus infection is complicated by a variety of resistance mechanisms that have evolved over time. In fact, the first resistant isolate of S aureus emerged not long after penicillin’s debut into clinical practice, and now the majority of strains are resistant to penicillin.

Methicillin was designed to overcome this beta-lactamase resistance and became the treatment of choice for penicillin-resistant S aureus isolates. However, MRSA isolates soon emerged because of the organism’s acquisition of penicillin-binding protein PBP2a via the mecA gene, leading to decreased binding affinity of methicillin.³

Since then, several agents active against MRSA (vancomycin, daptomycin, linezolid, tigecycline) have been introduced and continue to be widely used. While vancomycin is considered the first-line option for a variety of MRSA infections, its use has been threatened because of the emergence of vancomycin-intermediate-resistant S aureus (VISA), S aureus strains displaying vancomycin heteroresistance (hVISA), and vancomycin-resistant S aureus (VRSA) strains.⁴

VISA and hVISA isolates emerged through sequential mutations that lead to autolytic activity and cell-wall thickening. In contrast, the mechanism of resistance in VRSA is by acquisition of the vanA resistance gene, which alters the binding site of vancomycin from d-alanine-d-alanine to d-alanine-d-lactate.⁵

Streptococcus pneumoniae resistance: A continuing problem

The prevalence of drug resistance in S pneumoniae has risen since the late 1990s. A 2013 report from the SENTRY Antimicrobial Surveillance Program stated that almost 20% of S pneumoniae isolates were resistant to amoxicillin-clavulanate, and similar trends have been observed for penicillin (14.8%) and ceftriaxone (11.7%).⁶

S pneumoniae resistance is acquired through modifications of the penicillin-binding proteins, namely PBP1a, PBP2b, PBP2x, and, less frequently, PBP2a. These modifications lead to decreased binding affinity for most beta-lactams.⁷

Clinical impact of multidrug-resistant S aureus and S pneumoniae

In 2011, the US Centers for Disease Control and Prevention reported an estimated 80,000 severe MRSA infections and 11,000 MRSA-related deaths in the United States.⁸ In the same report, drug-resistant S pneumoniae was estimated to be responsible for almost 1.2 million illnesses and 7,000 deaths per year, leading to upwards of $96 million in related medical costs.

While invasive drug-resistant S pneumoniae infections usually affect patients at the extremes of age (under age 5 and over age 65), they have had a serious impact on patients of all ages.⁸

In light of the increasing prevalence of multidrug-resistant organisms, newer antimicrobial agents with novel mechanisms of action are needed.

CEFTAROLINE: A BETA-LACTAM WITH ANTI-MRSA ACTIVITY

The cephalosporins, a class of beta-lactam antibiotics, were originally derived from the fungus Cephalosporium (now called Acremonium). There are now many agents in this class, each containing a nucleus consisting of a beta-lactam ring fused to a six-member dihydrothiazine ring, and two side chains that can be modified to affect antibacterial activity and pharmacokinetic properties.

Cephalosporins are typically categorized into “generations.” With some exceptions, the first- and second-generation agents have good activity against gram-positive microorganisms, including methicillin-susceptible S aureus—but not against MRSA. The third- and fourth-generation cephalosporins have better gram-negative activity, with many agents having activity against the gram-negative bacterium Pseudomonas aeruginosa.

Enterococcal isolates are intrinsically resistant to cephalosporins. Additionally, cephalosporins are not active against anaerobic bacteria, except for a subset of structurally unique second-generation cephalosporins, ie, cefotetan and cefoxitin.

Ceftaroline was synthesized with specific manipulations of the side chains to provide enhanced activity against MRSA and multidrug-resistant S pneumoniae isolates, making it the first available beta-lactam with this ability.

Mechanism of action

Ceftaroline binds to penicillin-binding proteins, inhibiting transpeptidation. This interaction blocks the final stage of peptidoglycan synthesis and inhibits bacterial cell wall formation, ultimately leading to cellular autolysis and microorganism death. Ceftaroline binds with high affinity to PBP2a and PBP2x, expanding its activity to encompass MRSA and penicillin-resistant S pneumoniae isolates.⁹

Spectrum of activity

Ceftaroline has in vitro activity against many gram-positive and gram-negative bacteria,^10–13 including (Table 1):

• Methicillin-susceptible and methicillin-resistant staphylococci
• VISA, VRSA, and hVISA
• Daptomycin-nonsusceptible S aureus
• Streptococcal species, including penicillin-resistant S pneumoniae
• Enterobacteriaceae, including Klebsiella pneumoniae, Klebsiella oxytoca, Escherichia coli, Citrobacter koseri, Citrobacter freundii, Enterobacter cloacae, Enterobacter aerogenes, Moraxella catarrhalis, Morganella morganii, and Proteus mirabilis.

Of note, ceftaroline is not active against Pseudomonas species, Enterococcus species, or Bacteroides fragilis. In addition, it is not active against the “atypical” respiratory pathogens Mycoplasma pneumoniae, Chlamydophila pneumoniae, and Legionella pneumophila.

Ceftaroline resistance

Gram-negative organisms appear to develop resistance to ceftaroline at rates similar to those observed with the other oxyimino-cephalosporins (eg, ceftriaxone). Ceftaroline is inactive against gram-negative organisms producing extended-spectrum beta-lactamases, including K pneumoniae carbapenemase and metallo-beta-lactamases.¹⁴ In addition, it induces the expression of AmpC beta-lactamases.

Although currently uncommon, resistance to ceftaroline has also been reported in S aureus strains.¹⁵ The mechanism of resistance is decreased binding affinity for PBP2a due to amino acid substitutions on the nonpenicillin-binding domains.¹⁵

Pharmacokinetic profile

An understanding of pharmacokinetics is key in optimizing the dose of antimicrobials so that the drugs are used most effectively and pathogens do not develop resistance to them.

Ceftaroline fosamil is a prodrug that, upon intravenous administration, is rapidly converted by phosphatase enzymes to its active moiety, ceftaroline. Its pharmacokinetic profile is summarized in Table 2.^16,17 Its volume of distribution is similar to that of the fourth-generation cephalosporin cefepime.

Ceftaroline is then hydrolyzed into its inactive metabolite, ceftaroline M-1. It undergoes little hepatic metabolism and lacks properties to make it a substrate, inhibitor, or inducer of the CYP450 enzyme system and therefore is not likely to cause notable CYP450-related drug-drug interactions.

Like most other beta-lactams, ceftaroline is primarily excreted by the kidneys. Furthermore, an estimated 21% of a dose is eliminated with each intermittent hemodialysis session. Therefore, renal and intermittent hemodialysis dose adjustments are necessary. The estimated elimination half-life is 2.6 hours, necessitating dosing two to three times daily, depending on the indication and infectious inoculum.

Ceftaroline dosing

Ceftaroline is available only in a parenteral preparation and is typically given at a dose of 600 mg every 12 hours.¹⁰ The intravenous infusion is given over 1 hour.

The current stability data require reconstituted ceftaroline to be used within 6 hours at room temperature and within 24 hours if refrigerated.¹⁰

Ceftaroline requires dosing adjustments for patients with renal insufficiency. Per the manufacturer, renal dosing adjustments are based on the creatinine clearance rate, as estimated by the Cockroft-Gault formula:

• Creatinine clearance > 50 mL/min: no dosage adjustment necessary
• Creatinine clearance > 30 to ≤ 50 mL/min: give 400 mg every 12 hours
• Creatinine clearance ≥ 15 to ≤ 30 mL/min: give 300 mg every 12 hours
• Creatinine clearance < 15 mL/min or on intermittent dialysis: give 200 mg every 12 hours.

Ongoing clinical trials are investigating a higher-dosing strategy of 600 mg every 8 hours for patients with community-acquired bacterial pneumonia at risk of MRSA bacteremia.¹⁸

CLINICAL TRIALS LEADING TO CEFTAROLINE’S APPROVAL

Ceftaroline was approved for the treatment of community-acquired bacterial pneumonia and acute bacterial skin and skin-structure infections due to susceptible pathogens on the basis of phase 3 comparator trials.

Community-acquired bacterial pneumonia: The FOCUS 1 and 2 trials

The efficacy and safety of ceftaroline in the treatment of community-acquired bacterial pneumonia was studied in two randomized, double-blind, noninferiority trials, known as Ceftaroline Community-acquired Pneumonia vs Ceftriaxone (FOCUS) 1 and FOCUS 2.^19,20

Patients were adults and not critically ill, as was reflected by their being in Pneumonia Outcomes Research Team (PORT) risk class III or IV (with class V indicating the highest risk of death). Therefore, the results may not be completely applicable to critically ill patients or those not admitted to the hospital. Of note, patients were excluded from the trials if they had infections known or thought to be due to MRSA or to atypical organisms.²¹ Baseline characteristics and patient demographics were similar between study groups in both trials.

A bacterial pathogen was identified in 26.1% of the patients included in the modified intent-to-treat analysis of the pooled data of the trials; the most common pathogens were S pneumoniae, methicillin-sensitive S aureus, Haemophilus influenzae, K pneumoniae, and E coli.²¹

Treatment. Patients received either ceftaroline 600 mg every 12 hours (or a lower dose based on renal function) or ceftriaxone 1 g every 24 hours. In addition, in the FOCUS 1 trial, patients in both treatment groups received clarithromycin 500 mg every 12 hours for the first day.¹⁹

Results. In both trials and in the integrated analysis, ceftaroline was noninferior to ceftriaxone (Table 3).²² In the integrated analysis of both trials, compared with the ceftriaxone group, the ceftaroline group had a higher clinical cure rate among patients classified as PORT risk class III (86.8% vs 79.2%, weighted treatment difference 12.6%, 95% confidence interval [CI] 1.3–13.8) and among patients who had not received prior antibiotic treatment (85.5% vs 74.9%, weighted treatment difference 11.2%, 95% CI 4.5–18.0).²¹

Acute bacterial skin and skin-structure infections: The CANVAS 1 and 2 trials

The efficacy and safety of ceftaroline in the treatment of complicated acute bacterial skin and skin-structure infections was studied in two randomized, double-blind trials: Ceftaroline Versus Vancomycin in Skin and Skin Structure Infections (CANVAS) 1 and CANVAS 2.^23,24

Patients. Adult patients with a diagnosis of community-acquired skin and skin-structure infections warranting at least 5 days of intravenous antimicrobial therapy were included in the trials. Important protocol exclusions were patients with diabetic foot ulcers, decubitus ulcers, burns, ulcers associated with peripheral vascular disease accompanied by osteomyelitis, and suspected P aeruginosa infections.²⁵ This limits the external validity of ceftaroline use in the aforementioned excluded patient populations.

Patients in each treatment group of the trials had similar demographic characteristics. The most common infections were cellulitis, major abscess requiring surgical intervention, wound infection, and infected ulcer. Bacteremia was present in 4.2% of patients in the ceftaroline group and in 3.8% of patients in the vancomycin-aztreonam group. The most common pathogen was S aureus. Methicillin resistance was present in 40% of the ceftaroline group and 34% of the control group.

Treatment. Patients received either ceftaroline 600 mg every 12 hours or the combination of vancomycin 1 g plus aztreonam 1 g given 12 hours, for 5 to 14 days.

Results. As assessed at a “test-of-cure” visit 8 to 15 days after the last dose of study medication, the efficacy of ceftaroline was similar to that of vancomycin-aztreonam, meeting the set noninferiority goal (Table 4).²⁵ Moreover, if assessed on day 2 or 3 (a new end point recommended by the FDA), the rate of cessation of erythema spread and absence of fever was higher in the ceftaroline group than in the vancomycin-aztreonam group.²⁶ However, this end point was not in the original trial protocol.

CEFTAROLINE FOR OTHER INDICATIONS

As noted, ceftaroline has been approved for treating community-acquired bacterial pneumonia and acute bacterial skin and skin-structure infections. In addition, it has been used in several studies in animals, and case reports of non-FDA approved indications including endocarditis and osteomyelitis have been published. Clinical trials are evaluating its use in pediatric patients, as well as for community-acquired bacterial pneumonia with risk for MRSA and for MRSA bacteremia.

Endocarditis

Animal studies have demonstrated ceftaroline to have bactericidal activity against MRSA and hVISA in endocarditis.²⁷

A few case series have been published describing ceftaroline’s use as salvage therapy for persistent MRSA bacteremia and endocarditis. For example, Ho et al²⁸ reported using it in three patients who had endocarditis as a source of their persistent bacteremia. All three patients had resolution of their MRSA bloodstream infection following ceftaroline therapy. The dosage was 600 mg every 8 hours, which is higher than in the manufacturer’s prescribing information.

Lin et al²⁹ reported using ceftaroline in five patients with either possible or probable endocarditis. Three of the five patients had clinical cure as defined by resolution or improvement of all signs and symptoms of infection, and not requiring further antimicrobial therapy.²⁹

More data from clinical trials would be beneficial in defining ceftaroline’s role in treating endocarditis caused by susceptible microorganisms.

Osteomyelitis

In animal studies of osteomyelitis, ceftaroline exhibited activity against MRSA in infected bone and joint fluid. Compared with vancomycin and linezolid, ceftaroline was associated with more significant decreases in bacterial load in the infected joint fluid, bone marrow, and bone.³⁰

Lin et al²⁹ gave ceftaroline to two patients with bone and joint infections, both of whom had received other therapies that had failed. The doses of ceftaroline were higher than those recommended in the prescribing information; clinical cure was noted in both cases following the switch.

These data come from case series, and more study of ceftaroline’s role in the treatment of osteomyelitis infections is warranted.

Meningitis

The use of ceftaroline in meningitis has been studied in rabbits. While ceftaroline penetrated into the cerebrospinal fluid in only negligible amounts in healthy rabbits (3% penetration), its penetration improved to 15% in animals with inflamed meninges. Ceftaroline cerebrospinal fluid levels in inflamed meninges were sufficient to provide bactericidal activity against penicillin-sensitive and resistant S pneumoniae strains as well as K pneumoniae and E coli strains.^31,32

REPORTED ADVERSE EFFECTS OF CEFTAROLINE

Overall, ceftaroline was well tolerated in clinical trials, and its safety profile was similar to those of the comparator agents (ceftriaxone and vancomycin-aztreonam).

As with the other cephalosporins, hypersensitivity reactions have been reported with ceftaroline. In the clinical trials, 3% of patients developed a rash with ceftaroline.^33,34 Patients with a history of beta-lactam allergy were excluded from the trials, so the rate of cross-reactivity with penicillins and with other cephalosporins is unknown.

In the phase 3 clinical trials, gastrointestinal side effects including diarrhea (5%), nausea (4%), and vomiting (2%) were reported with ceftaroline. C difficile-associated diarrhea has also been reported.³³

As with other cephalosporins, ceftaroline can cause a false-positive result on the Coombs test. Approximately 11% of ceftaroline-treated patients in phase 3 clinical trials had a positive Coombs test, but hemolytic anemia did not occur in any patients.^33,34

Discontinuation of ceftaroline due to an adverse reaction was reported in 2.7% of patients receiving the drug during phase 3 trials, compared with 3.7% with comparator agents.

WHEN SHOULD CEFTAROLINE BE USED IN DAILY PRACTICE?

Ceftaroline has been shown to be at least as effective as ceftriaxone in treating community-acquired bacterial pneumonia, and at least as effective as vancomycin-aztreonam in treating acute bacterial skin and skin-structure infections. The 2014 Infectious Diseases Society of America’s guidelines for the diagnosis and management of skin and soft-tissue infections recommend ceftaroline as an option for empiric therapy for purulent skin and soft-tissue infections.³⁵

The guidelines on community-acquired pneumonia have not been updated since 2007, which was before ceftaroline was approved. However, these guidelines are currently undergoing revision and may provide insight on ceftaroline’s place in the treatment of community-acquired bacterial pneumonia.³⁶

Currently, ceftaroline’s routine use for these indications should be balanced by its higher cost ($150 for a 600-mg dose) compared with ceftriaxone ($5 for a 1-g dose) or vancomycin ($25 for a 1-g dose). The drug’s in vitro activity against drug-resistant pneumococci and S aureus, including MRSA, hVISA, and VISA may help fill an unmet need or provide a safer and more tolerable alternative to currently available therapies.

However, ceftaroline’s lack of activity against P aeruginosa and carbapenem-resistant Enterobacteriaceae does not meet the public health threat needs stemming from these multidrug-resistant microorganisms. Ongoing clinical trials in patients with more serious MRSA infections will provide important information about ceftaroline’s role as an anti-MRSA agent.

While the discovery of antimicrobials has had one of the greatest impacts on medicine, continued antibiotic use is threatened by the emergence of drug-resistant pathogens. Therefore, it is as important as ever to be good stewards of our currently available antimicrobials. Developing usage and dosing criteria for antimicrobials based on available data and literature is a step forward in optimizing the use of antibiotics—a precious medical resource.

In the first report evaluating the impact of a clinical guideline that calls for the use of postoperative continuous electroencephalography (CEEG) on infants after they’ve had cardiopulmonary bypass surgery, investigators at Children’s Hospital of Philadelphia and the University of Pennsylvania validated the clinical utility of routine CEEG monitoring and found that clinical assessment for seizures without CEEG is not a reliable marker for diagnosis and treatment.

In a report online in the Journal of Thoracic and Cardiovascular Surgery (J. Thorac. Cardiovasc. Surg. 2015 [doi:10.1016/j.jtcvs.2015.03.045]), Dr. Maryam Naim and colleagues said that CEEG identified electroencephalographic seizures in 8% of newborns after cardiopulmonary bypass surgery. The study, conducted over 18 months, evaluated 172 newborns, none older than 1 month, with 161 (94%) having undergone postoperative CEEG. They had CEEG within 6 hours of their return to the cardiac intensive care unit.

Courtesy of JTCVS/AATS

The study classified electroencephalographic seizures as EEG-only (also termed nonconvulsive seizures, with no observable clinical signs either at bedside or via video) or electroclinical seizures. Dr. Naim and colleagues said the majority of seizures they identified with CEEG would not have been noticed otherwise as they had no clinically obvious signs or symptoms.

The American Clinical Neurophysiology Society (ACNS) recommends that cardiac surgeons consider continuous CEEG monitoring in high-risk neonates with congenital heart disease (CHD) after bypass surgery, but Dr. Naim and coauthors raised the question of whether seizure incidence would justify routine CEEG for all neonates with CHD who’ve had bypass surgery, especially as health systems place greater emphasis on quality improvement programs and cost-effective strategies. The authors said that neonates with all types of congenital heart disease had seizures.

“In adult populations, CEEG has not been shown to significantly increase hospital costs, but cost-effectiveness analyses have not been performed in neonates with CHD,” the authors said.

So they attempted to identify at-risk populations of newborns who would benefit most from routine CEEG monitoring. In a multivariable model that the investigators used, both delayed sternal closure and longer deep hypothermic circulatory arrest (DHCA) during surgery seemed predictive of seizures, but the odds ratios for both were low, “suggesting the statistically significant findings may not be very useful in focusing CEEG implementation on a high-risk group.”

Previous studies have reported that identifying and treating seizures in newborns who have had bypass surgery may reduce secondary brain injury and improve outcomes (Pediatrics 2008;121:e759-67), and the Boston Circulatory Arrest Study showed an association between postoperative seizures and lower reading and math scores and lower cognitive and functional skills later in life (Circulation 2011;124:1361-1369). The authors cited other studies that showed older, critically ill children with “high seizure burdens” have had worse outcomes. (Critical Care Medicine 2013;31:215-23; Neurology 2014;82:396-404; Brain 2014;137:1429-38). They also pointed out increased risk if the seizure is not treated. “While occurrence of a seizure is a marker of brain injury, there may also be secondary injury if the seizure activity is not terminated,” Dr. Naim and coauthors said.

The investigators concluded that postoperative CEEG to identify seizures “is warranted,” and while they found some newborns may be at greater risk of postbypass seizures than others, they advocated for “widespread” monitoring strategies.

Their work also questioned the effectiveness of non-CEEG assessment. In the study, clinicians identified bedside events indicative of seizures – what the study termed “push-button events” – in 32 newborns, or about 18% of patients, but none of the events had an EEG correlate, so they were considered nonepileptic. When the authors looked more closely at those “push-button” events, they found they ranged from abnormal body movement in 14 and hypertension in 7 to tachycardia and abnormal face movements, among other characterizations, in lesser numbers.

“Furthermore, push-button events by bedside clinicians, including abnormal movements and hypertensive episodes concerning for possible seizures, did not have any EEG correlate, indicating that bedside clinical assessment for seizures without CEEG monitoring is unreliable,” Dr. Naim and colleagues said.

As to whether identifying and treating postbypass seizures in young newborns with CHD will improve long-term neurodevelopment in these children, the authors acknowledged that further study is needed.

They reported having no financial disclosures.

In the first report evaluating the impact of a clinical guideline that calls for the use of postoperative continuous electroencephalography (CEEG) on infants after they’ve had cardiopulmonary bypass surgery, investigators at Children’s Hospital of Philadelphia and the University of Pennsylvania validated the clinical utility of routine CEEG monitoring and found that clinical assessment for seizures without CEEG is not a reliable marker for diagnosis and treatment.

In a report online in the Journal of Thoracic and Cardiovascular Surgery (J. Thorac. Cardiovasc. Surg. 2015 [doi:10.1016/j.jtcvs.2015.03.045]), Dr. Maryam Naim and colleagues said that CEEG identified electroencephalographic seizures in 8% of newborns after cardiopulmonary bypass surgery. The study, conducted over 18 months, evaluated 172 newborns, none older than 1 month, with 161 (94%) having undergone postoperative CEEG. They had CEEG within 6 hours of their return to the cardiac intensive care unit.

Courtesy of JTCVS/AATS

The study classified electroencephalographic seizures as EEG-only (also termed nonconvulsive seizures, with no observable clinical signs either at bedside or via video) or electroclinical seizures. Dr. Naim and colleagues said the majority of seizures they identified with CEEG would not have been noticed otherwise as they had no clinically obvious signs or symptoms.

The American Clinical Neurophysiology Society (ACNS) recommends that cardiac surgeons consider continuous CEEG monitoring in high-risk neonates with congenital heart disease (CHD) after bypass surgery, but Dr. Naim and coauthors raised the question of whether seizure incidence would justify routine CEEG for all neonates with CHD who’ve had bypass surgery, especially as health systems place greater emphasis on quality improvement programs and cost-effective strategies. The authors said that neonates with all types of congenital heart disease had seizures.

“In adult populations, CEEG has not been shown to significantly increase hospital costs, but cost-effectiveness analyses have not been performed in neonates with CHD,” the authors said.

So they attempted to identify at-risk populations of newborns who would benefit most from routine CEEG monitoring. In a multivariable model that the investigators used, both delayed sternal closure and longer deep hypothermic circulatory arrest (DHCA) during surgery seemed predictive of seizures, but the odds ratios for both were low, “suggesting the statistically significant findings may not be very useful in focusing CEEG implementation on a high-risk group.”

Previous studies have reported that identifying and treating seizures in newborns who have had bypass surgery may reduce secondary brain injury and improve outcomes (Pediatrics 2008;121:e759-67), and the Boston Circulatory Arrest Study showed an association between postoperative seizures and lower reading and math scores and lower cognitive and functional skills later in life (Circulation 2011;124:1361-1369). The authors cited other studies that showed older, critically ill children with “high seizure burdens” have had worse outcomes. (Critical Care Medicine 2013;31:215-23; Neurology 2014;82:396-404; Brain 2014;137:1429-38). They also pointed out increased risk if the seizure is not treated. “While occurrence of a seizure is a marker of brain injury, there may also be secondary injury if the seizure activity is not terminated,” Dr. Naim and coauthors said.

The investigators concluded that postoperative CEEG to identify seizures “is warranted,” and while they found some newborns may be at greater risk of postbypass seizures than others, they advocated for “widespread” monitoring strategies.

Their work also questioned the effectiveness of non-CEEG assessment. In the study, clinicians identified bedside events indicative of seizures – what the study termed “push-button events” – in 32 newborns, or about 18% of patients, but none of the events had an EEG correlate, so they were considered nonepileptic. When the authors looked more closely at those “push-button” events, they found they ranged from abnormal body movement in 14 and hypertension in 7 to tachycardia and abnormal face movements, among other characterizations, in lesser numbers.

“Furthermore, push-button events by bedside clinicians, including abnormal movements and hypertensive episodes concerning for possible seizures, did not have any EEG correlate, indicating that bedside clinical assessment for seizures without CEEG monitoring is unreliable,” Dr. Naim and colleagues said.

As to whether identifying and treating postbypass seizures in young newborns with CHD will improve long-term neurodevelopment in these children, the authors acknowledged that further study is needed.

They reported having no financial disclosures.

In the first report evaluating the impact of a clinical guideline that calls for the use of postoperative continuous electroencephalography (CEEG) on infants after they’ve had cardiopulmonary bypass surgery, investigators at Children’s Hospital of Philadelphia and the University of Pennsylvania validated the clinical utility of routine CEEG monitoring and found that clinical assessment for seizures without CEEG is not a reliable marker for diagnosis and treatment.

In a report online in the Journal of Thoracic and Cardiovascular Surgery (J. Thorac. Cardiovasc. Surg. 2015 [doi:10.1016/j.jtcvs.2015.03.045]), Dr. Maryam Naim and colleagues said that CEEG identified electroencephalographic seizures in 8% of newborns after cardiopulmonary bypass surgery. The study, conducted over 18 months, evaluated 172 newborns, none older than 1 month, with 161 (94%) having undergone postoperative CEEG. They had CEEG within 6 hours of their return to the cardiac intensive care unit.

Courtesy of JTCVS/AATS

The study classified electroencephalographic seizures as EEG-only (also termed nonconvulsive seizures, with no observable clinical signs either at bedside or via video) or electroclinical seizures. Dr. Naim and colleagues said the majority of seizures they identified with CEEG would not have been noticed otherwise as they had no clinically obvious signs or symptoms.

The American Clinical Neurophysiology Society (ACNS) recommends that cardiac surgeons consider continuous CEEG monitoring in high-risk neonates with congenital heart disease (CHD) after bypass surgery, but Dr. Naim and coauthors raised the question of whether seizure incidence would justify routine CEEG for all neonates with CHD who’ve had bypass surgery, especially as health systems place greater emphasis on quality improvement programs and cost-effective strategies. The authors said that neonates with all types of congenital heart disease had seizures.

“In adult populations, CEEG has not been shown to significantly increase hospital costs, but cost-effectiveness analyses have not been performed in neonates with CHD,” the authors said.

So they attempted to identify at-risk populations of newborns who would benefit most from routine CEEG monitoring. In a multivariable model that the investigators used, both delayed sternal closure and longer deep hypothermic circulatory arrest (DHCA) during surgery seemed predictive of seizures, but the odds ratios for both were low, “suggesting the statistically significant findings may not be very useful in focusing CEEG implementation on a high-risk group.”

Previous studies have reported that identifying and treating seizures in newborns who have had bypass surgery may reduce secondary brain injury and improve outcomes (Pediatrics 2008;121:e759-67), and the Boston Circulatory Arrest Study showed an association between postoperative seizures and lower reading and math scores and lower cognitive and functional skills later in life (Circulation 2011;124:1361-1369). The authors cited other studies that showed older, critically ill children with “high seizure burdens” have had worse outcomes. (Critical Care Medicine 2013;31:215-23; Neurology 2014;82:396-404; Brain 2014;137:1429-38). They also pointed out increased risk if the seizure is not treated. “While occurrence of a seizure is a marker of brain injury, there may also be secondary injury if the seizure activity is not terminated,” Dr. Naim and coauthors said.

The investigators concluded that postoperative CEEG to identify seizures “is warranted,” and while they found some newborns may be at greater risk of postbypass seizures than others, they advocated for “widespread” monitoring strategies.

Their work also questioned the effectiveness of non-CEEG assessment. In the study, clinicians identified bedside events indicative of seizures – what the study termed “push-button events” – in 32 newborns, or about 18% of patients, but none of the events had an EEG correlate, so they were considered nonepileptic. When the authors looked more closely at those “push-button” events, they found they ranged from abnormal body movement in 14 and hypertension in 7 to tachycardia and abnormal face movements, among other characterizations, in lesser numbers.

“Furthermore, push-button events by bedside clinicians, including abnormal movements and hypertensive episodes concerning for possible seizures, did not have any EEG correlate, indicating that bedside clinical assessment for seizures without CEEG monitoring is unreliable,” Dr. Naim and colleagues said.

As to whether identifying and treating postbypass seizures in young newborns with CHD will improve long-term neurodevelopment in these children, the authors acknowledged that further study is needed.

They reported having no financial disclosures.

In the 1980s, human immunodeficiency virus (HIV) infection was considered untreatable and predictably lethal. Today, with highly effective antiretroviral therapy, it has become a chronic condition in which patients have a life expectancy comparable to that in the general population.

This change has led to new challenges for primary care physicians, many of whom now find themselves either the sole medical provider for or the comanager of aging HIV-infected patients. Given that about one-fifth of new HIV diagnoses are now in people over the age of 50, it is crucial that primary care providers be able to recognize and diagnose the disease in this population. In addition, they need to effectively manage the polypharmacy and subsequent drug interactions prevalent in older HIV-infected patients. Finally, the clinician must address comorbid diseases common in the elderly, specifically neurologic, cardiovascular, metabolic, and endocrine disorders, as well as performing routine cancer screening.

Take-home point

• As the number of people age 50 and older with HIV infection increases, primary care providers must be able to both recognize and manage the condition.

RISING PREVALENCE OF HIV IN THE ELDERLY

Globally, about 2.5 million people received a new diagnosis of HIV infection in 2011, and about 35 million people worldwide are currently living with it.¹ An estimated 1.1 million Americans are living with HIV, and of these, about 16% do not know they are infected.²

HIV patients who adhere to treatment and achieve a CD4 count above 350 and a low viral load have a normal life expectancy

Antiretroviral therapy has greatly improved the life expectancy of HIV-infected patients, and the number of HIV-infected people over age 50 continues to rise. A successfully treated HIV-positive person with a CD4 count higher than 350 × 10⁶/L and a suppressed viral load now has a normal life expectancy.³ In 2011, nearly 20% of newly diagnosed HIV-infected people in the United States were over age 50, as were nearly 25% of those with a new diagnosis of acquired immune deficiency syndrome (AIDS).⁴ This year (2015), we expect that more than half of all HIV-infected people in the United States will be over age 50.⁵

The rising prevalence of HIV infection in this age group has prompted reevaluation of screening guidelines. The US Preventive Services Task Force recommends screening for HIV in all people ages 15 to 65, and also after age 65 in people at ongoing risk of infection.⁶ The American College of Physicians has suggested that the range for routine HIV screening be expanded to age 75.⁷ The cost-effectiveness of expanded and more frequent HIV testing appears to justify it.⁸

Take-home points

• An HIV-infected patient who is compliant with an appropriate antiretroviral regimen and has a CD4 count higher than 350 × 10⁶/L and a suppressed viral load now has a normal life expectancy.
• Today, nearly 20% of newly diagnosed HIV-infected people and more than 50% of all HIV-infected people in the United States are over the age of 50.
• The age range for routine screening for HIV infection should be expanded.

HIGH-RISK GROUPS AMONG THE ELDERLY

Early in the HIV epidemic, older patients acquired HIV from blood transfusions received because of hemophilia and other disorders. However, this rapidly ceased after blood banks began screening blood products. Today, people over age 50 who acquire HIV have many of the same risk factors as younger people.

Men who have sex with men are the largest subgroup of HIV-infected people in the United States, even among those over age 50. In particular, white men who have sex with men now constitute the largest demographic group among the HIV-infected elderly.⁴

Intravenous drug users make up about 15% of older people with HIV.

Women who have sex with infected men or with men at risk of HIV infection make up the largest group of older women with HIV.⁴

Sex and the older person

Many older HIV-infected people remain sexually active and continue to engage in unprotected sexual intercourse far into advanced age. According to one survey, 53% of Americans ages 65 to 74 are engaging in sexual activity regularly; however, they are not using protective measures with up to 91% of casual partners and 70% of new partners.^9,10 Many widowed and divorced people are dating again, and they may be unfamiliar with condom use or may be reluctant to use condoms because condoms can often make it difficult to maintain an erection.

Drugs for erectile dysfunction are making it easier for the elderly to engage in both vaginal and anal intercourse, but often without a condom.⁹ Older women who no longer worry about getting pregnant may be less likely to insist their partners use a condom and to practice safe sex. In addition, age-related thinning and dryness can cause vaginal tears, increasing the risk of HIV transmission.¹¹

Take-home points

• People older than 50 have risk factors for HIV similar to those in younger people.
• Men who have sex with men compose the largest group of HIV-infected individuals in the elderly population.
• Unprotected sexual intercourse is common in the elderly for several reasons: unfamiliarity with condom use, difficulty maintaining an erection, lack of concern about possible pregnancy, and vaginal thinning and dryness in women.

UNDERDIAGNOSIS AND LATE DIAGNOSIS IN THE ELDERLY

The cumulative number of AIDS cases in adults age 50 and older increased nearly ninefold from 1990 to the end of 2009. Even more worrisome, one-half of HIV-positive adults over age 50 are diagnosed with AIDS simultaneously or within 1 year of their HIV diagnosis.⁴ This late diagnosis—and therefore late initiation of treatment—is associated with poorer health outcomes and more rapid disease progression.¹²

HIV infection in older adults often goes undiagnosed, for several reasons.

Providers may underestimate the risk in this population and therefore may not discuss HIV transmission or perform testing. Despite a US Centers for Disease Control and Prevention recommendation that people ages 13 to 64 be tested at least once, and more often if sexually active, only 35% of adults ages 45 to 64 have ever been tested for HIV infection.¹³

Age greater than 50 has been strongly associated with higher rates of non–AIDS-related cancers and cardiovascular disease

Older patients may not perceive themselves to be at risk of HIV infection because of lack of insight and information about its prevention and transmission. They are also less likely than younger adults to discuss their sexual habits or drug use with providers.¹⁴ In addition, compared with the young sexually active population, very little HIV prevention education is targeted to older people.¹⁵ Social stigmatization is also a concern for many HIV-infected elderly, as a perceived negative reputation within their community may prevent them from seeking care and disclosing their HIV status.

Take-home points

Reasons that HIV infection is underdiagnosed in the elderly include lack of:

• Provider recognition
• Insight and information about HIV prevention and transmission
• HIV-prevention education targeting the elderly
• Disclosure because of the social stigma of HIV infection.

HIV ACCELERATES AGING, AGING REDUCES IMMUNITY

Many HIV-positive people can expect to live as long as people in the general population, but those who are diagnosed late and thus are started on antiretroviral therapy later in the course of their infection have a reduced life expectancy. Longevity depends on both restoring the CD4 count to near-normal and suppressing the viral load to undetectable levels.^3,16 This is especially important for older adults, as HIV may accelerate aging, and aging itself may speed the progression of HIV disease, so that therapy may result in delayed or only partial restoration of immunity.

Older age at the time of HIV infection is a strong predictor of accelerated HIV disease progression in the absence of therapy.¹⁷ Left untreated, older patients with HIV lose CD4 cells and progress to AIDS and death faster than younger patients. The deleterious effects of chronic immune activation in the course of HIV infection, combined with the immune senescence of aging, are thought to promote this accelerated course.¹⁸

Recent data indicate that starting antiretroviral therapy early can help prevent the CD4-cell impairment that occurs with aging.¹⁹ However, in adults over age 50, the capacity to restore the CD4 count with antiretroviral therapy apears to be reduced, despite demonstrated viral load suppression and better adherence.²⁰ Although mean adherence rates appear higher in older HIV-infected patients, they are worse in those with neurocognitive impairment, highlighting the importance of evaluating neurocognition in this population.²¹

Decreased immune recovery and the subsequent increased risk of serious AIDS events are factors that now favor starting antiretroviral therapy in all HIV patients over age 50, regardless of CD4 count.

Take-home points

• Without treatment, HIV infection in older patients progresses more rapidly to AIDS and death than in younger patients.
• HIV-positive people over age 50 who have never received antiretroviral therapy should be strongly considered for it, regardless of the CD4 count.

SO MANY DRUGS, SO MANY INTERACTIONS

Since HIV patients are now living longer thanks to antiretroviral therapy, they are now experiencing more disease- and treatment-related problems. This has led to an increased likelihood of polypharmacy, defined here as the use of six or more medications.

In general, polypharmacy in the elderly is associated with adverse drug events, drug interactions, inappropriate medication use, delirium, falls, fractures, and poor medication adherence.^22,23 But it becomes even more of a problem in HIV-infected elderly patients, as various drug interactions can alter the effectiveness of the antiretroviral regimen and can result in drug toxicity.

The most common classes of medications used in the elderly are antihypertensives, lipid-lowering agents, antiplatelet medications, antidepressants, anxiolytics, sedatives, and analgesics, and many of these have notable interactions with current antiretroviral regimens.^24,25 Most medications, including antiretrovirals, are cleared by the liver or kidneys, and the function of these organs often decreases with age, resulting in impaired elimination and in drug accumulation.

Information on drug interactions is readily available from the US Department of Health and Human Services,²⁶ drug interaction databases,^27,28 and drug interaction software. The combination of antiretroviral therapy and preexisting polypharmacy significantly increases the risk of serious interactions, which can lead to drug toxicity, poorer adherence with antiretroviral therapy, loss of efficacy of the coadministered medication, or resurgence of HIV infection due to drug-drug interactions affecting the metabolism and ultimate efficacy of the antiretroviral therapy. An increased awareness of common drug-drug interactions can prevent coadministration of potentially harmful medications in elderly HIV patients.

Important interactions between antiretroviral drugs and other drug classes are summarized in Table 1.^25–28 Most notably:

• Simvastatin and lovastatin are contraindicated with any protease inhibitor.
• Proton pump inhibitors are not recommended for patients taking ritonavir-boosted atazanavir. If a proton pump inhibitor is necessary, the daily dose should not exceed 20 mg of omeprazole or its equivalent in patients who have never taken a protease inhibitor, and it should be taken 12 hours before boosted atazanavir.²⁶
• Corticosteroids, whether systemic, inhaled, or intranasal (eg, fluticasone, budesonide), should be avoided in combination with any protease inhibitor, as they can cause iatrogenic Cushing syndrome and also pose the risk of adrenal crisis during acute illness.²⁷

Take-home points

• In cases of preexisting polypharmacy, antiretroviral therapy can lead to significant drug toxicity, poor adherence to medications, and resurgence of HIV infection.
• Increased provider awareness of common drug-drug interactions can prevent the prescribing of potentially harmful drug combinations to HIV-infected elderly patients.

COMORBIDITIES

In recent years, more than half of the deaths in HIV patients on antiretroviral therapy have been from noninfectious comorbidities such as cardiovascular disease, bone disease, and renal failure, which often coexist and are associated with advanced age.²⁹ In fact, both older age and each additional year of antiretroviral therapy are independent predictors of polypathology (simultaneous occurrence of two or more defined diseases).³⁰ The Antiretroviral Therapy Cohort Collaboration found that age greater than 50 was strongly associated with increasing rates of non–AIDS-related malignancy and cardiovascular disease.³¹

CARDIOVASCULAR DISEASE

With the increasing life expectancy of HIV-infected adults on antiretroviral therapy, cardiovascular disease has become an important concern. HIV-infected adults appear to have a significantly greater risk of myocardial infarction and coronary artery disease than age-matched HIV-negative individuals.³² Strikingly, being older than 50 itself increases the risk of hospitalization for cardiovascular disease fivefold (incidence rate ratio 5.01, 95% confidence interval 3.41–7.38).³³ In addition, HIV infection is associated with a risk of acute myocardial infarction 50% higher than that explained by recognized risk factors.³⁴

This high prevalence of coronary artery disease is likely from a combination of factors, including increasing age and the chronic inflammation and immune activation associated with HIV infection.³⁵ An association between untreated HIV disease and markers of risk for cardiovascular disease has been identified.^36,37

HIV is associated with a 50% higher risk of acute myocardial infarction beyond traditional risk factors

In addition, antiretroviral therapy is associated with dyslipidemia, which is most pronounced with protease inhibitor regimens. Whether specific lipid changes associated with individual antiretroviral drugs affect cardiovascular risk remains uncertain. In the Data Collection on Adverse Events of Anti-HIV Drugs studies,³⁸ only cumulative exposure to indinavir, lopinavir-ritonavir, and didanosine was associated with an increased risk of myocardial infarction.³⁸

Traditional risk factors such as obesity, tobacco use, and genetic predisposition also apply to HIV-infected people.³⁹ In fact, the prevalence of traditional risk factors such as smoking and dyslipidemia is generally higher in HIV-infected people than in the general population, although this situation may be improving.⁴⁰

Science needs to elucidate the relationship between traditional and nontraditional risk factors for cardiovascular disease in older HIV-infected adults. In the meantime, older patients with HIV require aggressive management of modifiable risk factors.

Tools for assessing cardiovascular risk include the Framingham risk score⁴¹ and the Data Collection on Adverse Events of Anti-HIV Drugs 5-year risk calculator.⁴² The European AIDS Clinical Society guidelines recommend considering changing the antiretroviral regimen if the patient’s 10-year risk of cardiovascular disease is more than 20%.⁴³ Recommended strategies for reducing cardiovascular risk in elderly patients with HIV infection include counseling about smoking cessation and weight loss at every clinic visit and optimally controlling dyslipidemia and hypertension using nationally accepted standardized guidelines.⁴⁴

Take-home points

• HIV infection is associated with a 50% higher risk of acute myocardial infarction beyond that explained by traditional risk factors.
• Chronic inflammation, immune activation, and dyslipidemia associated with antiretroviral therapy all contribute to cardiovascular disease in HIV-infected patients.
• HIV-infected elderly patients require aggressive management of modifiable risk factors for cardiovascular disease.

ENDOCRINE DISEASE

Diabetes mellitus

The estimated prevalence of diabetes mellitus is 3% in HIV-infected people who have never received antiretroviral therapy, but glucose intolerance increases to the range of 10% to 25% in those who have started it.⁴⁵ Glucose disorders are associated with traditional risk factors as well as with HIV-associated factors such as lipodystrophy and antiretroviral therapy, specifically long-term use of protease inhibitors.⁴⁶ Although increasing age and obesity clearly play a role in the development of diabetes mellitus in this population, HIV-specific factors may also allow diabetes to develop at a lower level of adiposity than in people without HIV infection.⁴⁷

Strategies for preventing type 2 diabetes mellitus in HIV-infected patients focus on avoiding excessive weight gain, especially after starting antiretroviral therapy; regularly screening for diabetes using hemoglobin A_1c, both before and after starting antiretroviral therapy; and continuing to check hemoglobin A_1c every 6 months. The target hemoglobin A_1c should be less than 7.0%. This threshold should be increased to 8% in frail elderly adults if their anticipated life expectancy is less than 5 years, given their higher risk of hypoglycemia, polypharmacy, and drug interactions.⁴⁸ In addition, as in HIV-negative patients, diabetes screening should be performed if systolic blood pressure exceeds 135/80 mm Hg.

Insulin sensitizers such as metformin and thiazolidinediones should be considered for treating diabetes in HIV-infected patients if no contraindications exist. Consideration may also be given to switching the antiretroviral regimen from a protease inhibitor-based regimen to a nonnucleoside reverse transcriptase inhibitor-based regimen.⁴⁸

Take-home points

• Glucose intolerance has been associated with HIV-specific factors, including lipodystrophy and antiretroviral therapy.
• Avoiding excessive weight gain, use of insulin-sensitizing medications, and alteration in antiretroviral regimens should be considered for the treatment of diabetes mellitus in HIV infection.

Osteoporosis

Osteoporotic bone disease disproportionately affects patients with advanced HIV infection compared with patients of similar age.⁴⁹ Bone mineral density is lower and the fracture rate is higher in HIV-infected individuals.

The pathogenesis of bone disease appears to be multifactorial. Traditional risk factors include hypogonadism, smoking, alcohol use, and low body weight, while HIV-related risk factors include chronic immune activation and antiretroviral therapy.⁵⁰

Several antiretroviral regimens have been linked to clinically significant bone loss, including both tenofovir-based and protease inhibitor-based regimens.⁵¹ Most studies have shown that bone mineral density decreases by 2% to 6% in the first 2 years after starting these regimens⁵²; however, long-term effects on bone loss are unknown.

Questions remain. For example, what are the exact mechanisms that lead to the acute decrease in bone mineral density after starting antiretroviral therapy? And why is vitamin D deficiency is so prevalent in HIV infection, with low vitamin D levels seen in up to 60% to 75% of elderly HIV-infected patients?⁵³

Osteoporosis and vitamin D deficiency appear to be more prevalent with HIV infection

Both the Work Group for the HIV and Aging Consensus Project⁵⁴ and the European AIDS Clinical Society⁴³ recommend screening for and treating causes of secondary low bone mineral density in HIV-infected men over age 50 and postmenopausal HIV-infected women. These causes include vitamin D deficiency. As of 2013, the National Osteoporosis Foundation guidelines include HIV infection and antiretroviral therapy as osteoporosis risk factors that should trigger screening for low bone mineral density with dual-energy x-ray absorptiometry (DXA).⁵⁵

As in the general population, the preferred treatment for low bone mineral density in people with HIV is a bisphosphonate, in addition to ensuring adequate calcium and vitamin D intake. It is important to repeat DXA imaging every 2 years and to reassess the need for continued bisphosphonate therapy after 3 to 5 years because of a possible increased risk of fracture with prolonged use.

Take-home points

• Osteoporosis and vitamin D deficiency both appear to be more prevalent with HIV infection.
• HIV infection and antiretroviral therapy are risk factors that should prompt DXA screening to evaluate for osteoporosis.

NEUROCOGNITIVE DISORDERS

HIV-associated neurocognitive disorders are common, with an estimated 50% of HIV-infected patients experiencing some degree of cognitive loss and some progressing to dementia.⁵⁶ Unfortunately, studies suggest that cognitive disorders can occur despite good HIV control with antiretroviral therapy, with one report demonstrating that 84% of patients with cognitive complaints and 64% without complaints were affected by an HIV-associated neurocognitive disorder.⁵⁷

HIV-associated dementia is often subcortical, with fluctuating symptoms such as psychomotor retardation, difficulty multitasking, and apathy. In contrast to dementia syndromes such as Alzheimer disease, relentless progression is less common in HIV-infected patients who receive antiretroviral therapy.

The Mini-Mental State Examination should not be used to screen for HIV-associated neurocognitive disorders, as it does not assess the domains that are typically impaired. The Montreal Cognitive Assessment has been suggested as the best screening instrument in elderly HIV-infected patients; it is available at no cost at www.mocatest.org.⁵⁸

As HIV-associated neurocognitive disorder is a diagnosis of exclusion, an evaluation for alternative diagnoses such as syphilis, hypothyroidism, and depression is recommended. If an HIV-associated neurocognitive disorder is diagnosed, referral to specialty care should be considered, as interventions such as lumbar puncture to assess cerebrospinal fluid viral escape and changing the antiretroviral regimen to improve central nervous system penetration are possible options under study.

Patients with poorly controlled HIV and a depressed CD4 count are at risk of a number of central nervous system complications in addition to HIV-associated neurocognitive disorders, eg, central nervous system toxoplasmosis, cryptococcal meningitis, progressive multifocal leukoencephalopathy, and primary central nervous system lymphoma. Adherence to an effective antiretroviral regimen is the primary prevention strategy.

Take-home points

• HIV-associated neurocognitive disorders and dementia can occur despite appropriate HIV control and adherence to antiretroviral therapy.
• Adherence to antiretroviral therapy is the primary prevention against most central nervous system complications in HIV infection.

GERIATRIC SYNDROMES

The aging HIV-infected adult may also be at increased risk of geriatric syndromes.

HIV-infected men are 4.5 to 10 times more likely than age-matched controls to be frail

In particular, a frailty-related phenotype of weight loss, exhaustion, slowness, and low physical activity was more common in HIV-infected elderly than in noninfected elderly.⁵⁹ HIV-infected men are 4.5 to 10 times more likely than age-matched controls to be frail, and the likelihood of frailty increases with age, duration of HIV infection, having a CD4 count lower than 350 × 10⁶/L, and having uncontrolled HIV replication.^60,61

Other geriatric syndromes such as falls, urinary incontinence, and functional impairment have been identified in 25% to 56% of older HIV-infected patients.⁶² Indeed, the combination of HIV and older age may adversely affect performance of instrumental activities of daily living.⁶³ Also, as previously mentioned, nondisclosure, fear of HIV-related social stigmatization, and a desire to be self-reliant are all factors that perpetuate the social isolation that is common among the HIV-infected elderly.

For these reasons, a comprehensive approach involving a geriatrician, an infectious disease specialist, and community social workers is needed to manage the care of this aging population.

Take-home point

• Geriatric syndromes have an important impact on health in aging HIV patients.

CANCER SCREENING IN HIV PATIENTS

People with HIV have an elevated risk of cancer. Specifically, compared with the general population, their risk is:

• 3,640 times higher for Kaposi sarcoma
• 77 times higher for non-Hodgkin lymphomas
• 6 times higher for cervical cancer.^64,65

These cancers are considered “AIDS-defining,” and fortunately, the development of effective antiretroviral therapy in the 1990s has led to a marked reduction in their incidence. However, the aging HIV population is now experiencing a rise in the incidence of non–AIDS-defining cancers, such as cancers of the lung, liver, kidney, anus, head and neck, and skin, as well as Hodgkin lymphoma.⁶⁶ Table 2 shows the standardized incidence ratio of selected non–AIDS-defining cancers in HIV-infected patients as reported in several large international studies.^65,67,68 The etiology for the increased risk of non–AIDS-defining cancers in the HIV-infected population is not clear, but possible explanations include the virus itself, antiretroviral therapy, and co-infection with other viruses such as hepatitis B, hepatitis C, and Epstein-Barr virus.

Guidelines for cancer screening vary by organization, and the American Cancer Society, the National Cancer Institute, and the US Preventive Services Task Force do not have formal screening guidelines for the most common non–AIDS-defining cancers. The European AIDS Clinical Society, however, has proposed some screening recommendations for selected malignancies.⁴³

In general, screening recommendations are similar to those for HIV-negative patients. A specific difference for HIV-infected patients is in cervical cancer screening. HIV-infected women should undergo a Papanicolaou smear at 6-month intervals during the first year after diagnosis of HIV infection and, if the results are normal, annually thereafter. There is no consensus as to whether human papillomavirus testing should be performed routinely on HIV-infected women.

At the time of this writing, there are no recommendations for routine screening for anal cancer, although some specialists recommend anal cytologic screening for HIV-positive men and women, and an annual digital anal examination may be useful to detect masses that could be anal cancer.⁶⁹

Take-home points

• The incidence of non–AIDS-defining cancers is rising in the aging HIV population.
• There are currently no formal recommendations for routine screening for anal cancer.

FINAL WORD

Because patients with HIV are living longer as a result of newer effective combination antiretroviral therapies, physicians face a new challenge of managing conditions in these patients that are traditionally associated with aging. Providers will need to improve their understanding of drug-drug interactions and polypharmacy issues and be able to address the complex medical and psychosocial issues in this growing population. As patients with HIV on effective antiretroviral therapy grow older, the burden of comorbid medical disease will continue to increase.

In the 1980s, human immunodeficiency virus (HIV) infection was considered untreatable and predictably lethal. Today, with highly effective antiretroviral therapy, it has become a chronic condition in which patients have a life expectancy comparable to that in the general population.

This change has led to new challenges for primary care physicians, many of whom now find themselves either the sole medical provider for or the comanager of aging HIV-infected patients. Given that about one-fifth of new HIV diagnoses are now in people over the age of 50, it is crucial that primary care providers be able to recognize and diagnose the disease in this population. In addition, they need to effectively manage the polypharmacy and subsequent drug interactions prevalent in older HIV-infected patients. Finally, the clinician must address comorbid diseases common in the elderly, specifically neurologic, cardiovascular, metabolic, and endocrine disorders, as well as performing routine cancer screening.

Take-home point

• As the number of people age 50 and older with HIV infection increases, primary care providers must be able to both recognize and manage the condition.

RISING PREVALENCE OF HIV IN THE ELDERLY

Globally, about 2.5 million people received a new diagnosis of HIV infection in 2011, and about 35 million people worldwide are currently living with it.¹ An estimated 1.1 million Americans are living with HIV, and of these, about 16% do not know they are infected.²

HIV patients who adhere to treatment and achieve a CD4 count above 350 and a low viral load have a normal life expectancy

Antiretroviral therapy has greatly improved the life expectancy of HIV-infected patients, and the number of HIV-infected people over age 50 continues to rise. A successfully treated HIV-positive person with a CD4 count higher than 350 × 10⁶/L and a suppressed viral load now has a normal life expectancy.³ In 2011, nearly 20% of newly diagnosed HIV-infected people in the United States were over age 50, as were nearly 25% of those with a new diagnosis of acquired immune deficiency syndrome (AIDS).⁴ This year (2015), we expect that more than half of all HIV-infected people in the United States will be over age 50.⁵

The rising prevalence of HIV infection in this age group has prompted reevaluation of screening guidelines. The US Preventive Services Task Force recommends screening for HIV in all people ages 15 to 65, and also after age 65 in people at ongoing risk of infection.⁶ The American College of Physicians has suggested that the range for routine HIV screening be expanded to age 75.⁷ The cost-effectiveness of expanded and more frequent HIV testing appears to justify it.⁸

Take-home points

• An HIV-infected patient who is compliant with an appropriate antiretroviral regimen and has a CD4 count higher than 350 × 10⁶/L and a suppressed viral load now has a normal life expectancy.
• Today, nearly 20% of newly diagnosed HIV-infected people and more than 50% of all HIV-infected people in the United States are over the age of 50.
• The age range for routine screening for HIV infection should be expanded.

HIGH-RISK GROUPS AMONG THE ELDERLY

Early in the HIV epidemic, older patients acquired HIV from blood transfusions received because of hemophilia and other disorders. However, this rapidly ceased after blood banks began screening blood products. Today, people over age 50 who acquire HIV have many of the same risk factors as younger people.

Men who have sex with men are the largest subgroup of HIV-infected people in the United States, even among those over age 50. In particular, white men who have sex with men now constitute the largest demographic group among the HIV-infected elderly.⁴

Intravenous drug users make up about 15% of older people with HIV.

Women who have sex with infected men or with men at risk of HIV infection make up the largest group of older women with HIV.⁴

Sex and the older person

Many older HIV-infected people remain sexually active and continue to engage in unprotected sexual intercourse far into advanced age. According to one survey, 53% of Americans ages 65 to 74 are engaging in sexual activity regularly; however, they are not using protective measures with up to 91% of casual partners and 70% of new partners.^9,10 Many widowed and divorced people are dating again, and they may be unfamiliar with condom use or may be reluctant to use condoms because condoms can often make it difficult to maintain an erection.

Drugs for erectile dysfunction are making it easier for the elderly to engage in both vaginal and anal intercourse, but often without a condom.⁹ Older women who no longer worry about getting pregnant may be less likely to insist their partners use a condom and to practice safe sex. In addition, age-related thinning and dryness can cause vaginal tears, increasing the risk of HIV transmission.¹¹

Take-home points

• People older than 50 have risk factors for HIV similar to those in younger people.
• Men who have sex with men compose the largest group of HIV-infected individuals in the elderly population.
• Unprotected sexual intercourse is common in the elderly for several reasons: unfamiliarity with condom use, difficulty maintaining an erection, lack of concern about possible pregnancy, and vaginal thinning and dryness in women.

UNDERDIAGNOSIS AND LATE DIAGNOSIS IN THE ELDERLY

The cumulative number of AIDS cases in adults age 50 and older increased nearly ninefold from 1990 to the end of 2009. Even more worrisome, one-half of HIV-positive adults over age 50 are diagnosed with AIDS simultaneously or within 1 year of their HIV diagnosis.⁴ This late diagnosis—and therefore late initiation of treatment—is associated with poorer health outcomes and more rapid disease progression.¹²

HIV infection in older adults often goes undiagnosed, for several reasons.

Providers may underestimate the risk in this population and therefore may not discuss HIV transmission or perform testing. Despite a US Centers for Disease Control and Prevention recommendation that people ages 13 to 64 be tested at least once, and more often if sexually active, only 35% of adults ages 45 to 64 have ever been tested for HIV infection.¹³

Age greater than 50 has been strongly associated with higher rates of non–AIDS-related cancers and cardiovascular disease

Older patients may not perceive themselves to be at risk of HIV infection because of lack of insight and information about its prevention and transmission. They are also less likely than younger adults to discuss their sexual habits or drug use with providers.¹⁴ In addition, compared with the young sexually active population, very little HIV prevention education is targeted to older people.¹⁵ Social stigmatization is also a concern for many HIV-infected elderly, as a perceived negative reputation within their community may prevent them from seeking care and disclosing their HIV status.

Take-home points

Reasons that HIV infection is underdiagnosed in the elderly include lack of:

• Provider recognition
• Insight and information about HIV prevention and transmission
• HIV-prevention education targeting the elderly
• Disclosure because of the social stigma of HIV infection.

HIV ACCELERATES AGING, AGING REDUCES IMMUNITY

Many HIV-positive people can expect to live as long as people in the general population, but those who are diagnosed late and thus are started on antiretroviral therapy later in the course of their infection have a reduced life expectancy. Longevity depends on both restoring the CD4 count to near-normal and suppressing the viral load to undetectable levels.^3,16 This is especially important for older adults, as HIV may accelerate aging, and aging itself may speed the progression of HIV disease, so that therapy may result in delayed or only partial restoration of immunity.

Older age at the time of HIV infection is a strong predictor of accelerated HIV disease progression in the absence of therapy.¹⁷ Left untreated, older patients with HIV lose CD4 cells and progress to AIDS and death faster than younger patients. The deleterious effects of chronic immune activation in the course of HIV infection, combined with the immune senescence of aging, are thought to promote this accelerated course.¹⁸

Recent data indicate that starting antiretroviral therapy early can help prevent the CD4-cell impairment that occurs with aging.¹⁹ However, in adults over age 50, the capacity to restore the CD4 count with antiretroviral therapy apears to be reduced, despite demonstrated viral load suppression and better adherence.²⁰ Although mean adherence rates appear higher in older HIV-infected patients, they are worse in those with neurocognitive impairment, highlighting the importance of evaluating neurocognition in this population.²¹

Decreased immune recovery and the subsequent increased risk of serious AIDS events are factors that now favor starting antiretroviral therapy in all HIV patients over age 50, regardless of CD4 count.

Take-home points

• Without treatment, HIV infection in older patients progresses more rapidly to AIDS and death than in younger patients.
• HIV-positive people over age 50 who have never received antiretroviral therapy should be strongly considered for it, regardless of the CD4 count.

SO MANY DRUGS, SO MANY INTERACTIONS

Since HIV patients are now living longer thanks to antiretroviral therapy, they are now experiencing more disease- and treatment-related problems. This has led to an increased likelihood of polypharmacy, defined here as the use of six or more medications.

In general, polypharmacy in the elderly is associated with adverse drug events, drug interactions, inappropriate medication use, delirium, falls, fractures, and poor medication adherence.^22,23 But it becomes even more of a problem in HIV-infected elderly patients, as various drug interactions can alter the effectiveness of the antiretroviral regimen and can result in drug toxicity.

The most common classes of medications used in the elderly are antihypertensives, lipid-lowering agents, antiplatelet medications, antidepressants, anxiolytics, sedatives, and analgesics, and many of these have notable interactions with current antiretroviral regimens.^24,25 Most medications, including antiretrovirals, are cleared by the liver or kidneys, and the function of these organs often decreases with age, resulting in impaired elimination and in drug accumulation.

Information on drug interactions is readily available from the US Department of Health and Human Services,²⁶ drug interaction databases,^27,28 and drug interaction software. The combination of antiretroviral therapy and preexisting polypharmacy significantly increases the risk of serious interactions, which can lead to drug toxicity, poorer adherence with antiretroviral therapy, loss of efficacy of the coadministered medication, or resurgence of HIV infection due to drug-drug interactions affecting the metabolism and ultimate efficacy of the antiretroviral therapy. An increased awareness of common drug-drug interactions can prevent coadministration of potentially harmful medications in elderly HIV patients.

Important interactions between antiretroviral drugs and other drug classes are summarized in Table 1.^25–28 Most notably:

• Simvastatin and lovastatin are contraindicated with any protease inhibitor.
• Proton pump inhibitors are not recommended for patients taking ritonavir-boosted atazanavir. If a proton pump inhibitor is necessary, the daily dose should not exceed 20 mg of omeprazole or its equivalent in patients who have never taken a protease inhibitor, and it should be taken 12 hours before boosted atazanavir.²⁶
• Corticosteroids, whether systemic, inhaled, or intranasal (eg, fluticasone, budesonide), should be avoided in combination with any protease inhibitor, as they can cause iatrogenic Cushing syndrome and also pose the risk of adrenal crisis during acute illness.²⁷

Take-home points

• In cases of preexisting polypharmacy, antiretroviral therapy can lead to significant drug toxicity, poor adherence to medications, and resurgence of HIV infection.
• Increased provider awareness of common drug-drug interactions can prevent the prescribing of potentially harmful drug combinations to HIV-infected elderly patients.

COMORBIDITIES

In recent years, more than half of the deaths in HIV patients on antiretroviral therapy have been from noninfectious comorbidities such as cardiovascular disease, bone disease, and renal failure, which often coexist and are associated with advanced age.²⁹ In fact, both older age and each additional year of antiretroviral therapy are independent predictors of polypathology (simultaneous occurrence of two or more defined diseases).³⁰ The Antiretroviral Therapy Cohort Collaboration found that age greater than 50 was strongly associated with increasing rates of non–AIDS-related malignancy and cardiovascular disease.³¹

CARDIOVASCULAR DISEASE

With the increasing life expectancy of HIV-infected adults on antiretroviral therapy, cardiovascular disease has become an important concern. HIV-infected adults appear to have a significantly greater risk of myocardial infarction and coronary artery disease than age-matched HIV-negative individuals.³² Strikingly, being older than 50 itself increases the risk of hospitalization for cardiovascular disease fivefold (incidence rate ratio 5.01, 95% confidence interval 3.41–7.38).³³ In addition, HIV infection is associated with a risk of acute myocardial infarction 50% higher than that explained by recognized risk factors.³⁴

This high prevalence of coronary artery disease is likely from a combination of factors, including increasing age and the chronic inflammation and immune activation associated with HIV infection.³⁵ An association between untreated HIV disease and markers of risk for cardiovascular disease has been identified.^36,37

HIV is associated with a 50% higher risk of acute myocardial infarction beyond traditional risk factors

In addition, antiretroviral therapy is associated with dyslipidemia, which is most pronounced with protease inhibitor regimens. Whether specific lipid changes associated with individual antiretroviral drugs affect cardiovascular risk remains uncertain. In the Data Collection on Adverse Events of Anti-HIV Drugs studies,³⁸ only cumulative exposure to indinavir, lopinavir-ritonavir, and didanosine was associated with an increased risk of myocardial infarction.³⁸

Traditional risk factors such as obesity, tobacco use, and genetic predisposition also apply to HIV-infected people.³⁹ In fact, the prevalence of traditional risk factors such as smoking and dyslipidemia is generally higher in HIV-infected people than in the general population, although this situation may be improving.⁴⁰

Science needs to elucidate the relationship between traditional and nontraditional risk factors for cardiovascular disease in older HIV-infected adults. In the meantime, older patients with HIV require aggressive management of modifiable risk factors.

Tools for assessing cardiovascular risk include the Framingham risk score⁴¹ and the Data Collection on Adverse Events of Anti-HIV Drugs 5-year risk calculator.⁴² The European AIDS Clinical Society guidelines recommend considering changing the antiretroviral regimen if the patient’s 10-year risk of cardiovascular disease is more than 20%.⁴³ Recommended strategies for reducing cardiovascular risk in elderly patients with HIV infection include counseling about smoking cessation and weight loss at every clinic visit and optimally controlling dyslipidemia and hypertension using nationally accepted standardized guidelines.⁴⁴

Take-home points

• HIV infection is associated with a 50% higher risk of acute myocardial infarction beyond that explained by traditional risk factors.
• Chronic inflammation, immune activation, and dyslipidemia associated with antiretroviral therapy all contribute to cardiovascular disease in HIV-infected patients.
• HIV-infected elderly patients require aggressive management of modifiable risk factors for cardiovascular disease.

ENDOCRINE DISEASE

Diabetes mellitus

The estimated prevalence of diabetes mellitus is 3% in HIV-infected people who have never received antiretroviral therapy, but glucose intolerance increases to the range of 10% to 25% in those who have started it.⁴⁵ Glucose disorders are associated with traditional risk factors as well as with HIV-associated factors such as lipodystrophy and antiretroviral therapy, specifically long-term use of protease inhibitors.⁴⁶ Although increasing age and obesity clearly play a role in the development of diabetes mellitus in this population, HIV-specific factors may also allow diabetes to develop at a lower level of adiposity than in people without HIV infection.⁴⁷

Strategies for preventing type 2 diabetes mellitus in HIV-infected patients focus on avoiding excessive weight gain, especially after starting antiretroviral therapy; regularly screening for diabetes using hemoglobin A_1c, both before and after starting antiretroviral therapy; and continuing to check hemoglobin A_1c every 6 months. The target hemoglobin A_1c should be less than 7.0%. This threshold should be increased to 8% in frail elderly adults if their anticipated life expectancy is less than 5 years, given their higher risk of hypoglycemia, polypharmacy, and drug interactions.⁴⁸ In addition, as in HIV-negative patients, diabetes screening should be performed if systolic blood pressure exceeds 135/80 mm Hg.

Insulin sensitizers such as metformin and thiazolidinediones should be considered for treating diabetes in HIV-infected patients if no contraindications exist. Consideration may also be given to switching the antiretroviral regimen from a protease inhibitor-based regimen to a nonnucleoside reverse transcriptase inhibitor-based regimen.⁴⁸

Take-home points

• Glucose intolerance has been associated with HIV-specific factors, including lipodystrophy and antiretroviral therapy.
• Avoiding excessive weight gain, use of insulin-sensitizing medications, and alteration in antiretroviral regimens should be considered for the treatment of diabetes mellitus in HIV infection.

Osteoporosis

Osteoporotic bone disease disproportionately affects patients with advanced HIV infection compared with patients of similar age.⁴⁹ Bone mineral density is lower and the fracture rate is higher in HIV-infected individuals.

The pathogenesis of bone disease appears to be multifactorial. Traditional risk factors include hypogonadism, smoking, alcohol use, and low body weight, while HIV-related risk factors include chronic immune activation and antiretroviral therapy.⁵⁰

Several antiretroviral regimens have been linked to clinically significant bone loss, including both tenofovir-based and protease inhibitor-based regimens.⁵¹ Most studies have shown that bone mineral density decreases by 2% to 6% in the first 2 years after starting these regimens⁵²; however, long-term effects on bone loss are unknown.

Questions remain. For example, what are the exact mechanisms that lead to the acute decrease in bone mineral density after starting antiretroviral therapy? And why is vitamin D deficiency is so prevalent in HIV infection, with low vitamin D levels seen in up to 60% to 75% of elderly HIV-infected patients?⁵³

Osteoporosis and vitamin D deficiency appear to be more prevalent with HIV infection

Both the Work Group for the HIV and Aging Consensus Project⁵⁴ and the European AIDS Clinical Society⁴³ recommend screening for and treating causes of secondary low bone mineral density in HIV-infected men over age 50 and postmenopausal HIV-infected women. These causes include vitamin D deficiency. As of 2013, the National Osteoporosis Foundation guidelines include HIV infection and antiretroviral therapy as osteoporosis risk factors that should trigger screening for low bone mineral density with dual-energy x-ray absorptiometry (DXA).⁵⁵

As in the general population, the preferred treatment for low bone mineral density in people with HIV is a bisphosphonate, in addition to ensuring adequate calcium and vitamin D intake. It is important to repeat DXA imaging every 2 years and to reassess the need for continued bisphosphonate therapy after 3 to 5 years because of a possible increased risk of fracture with prolonged use.

Take-home points

• Osteoporosis and vitamin D deficiency both appear to be more prevalent with HIV infection.
• HIV infection and antiretroviral therapy are risk factors that should prompt DXA screening to evaluate for osteoporosis.

NEUROCOGNITIVE DISORDERS

HIV-associated neurocognitive disorders are common, with an estimated 50% of HIV-infected patients experiencing some degree of cognitive loss and some progressing to dementia.⁵⁶ Unfortunately, studies suggest that cognitive disorders can occur despite good HIV control with antiretroviral therapy, with one report demonstrating that 84% of patients with cognitive complaints and 64% without complaints were affected by an HIV-associated neurocognitive disorder.⁵⁷

HIV-associated dementia is often subcortical, with fluctuating symptoms such as psychomotor retardation, difficulty multitasking, and apathy. In contrast to dementia syndromes such as Alzheimer disease, relentless progression is less common in HIV-infected patients who receive antiretroviral therapy.

The Mini-Mental State Examination should not be used to screen for HIV-associated neurocognitive disorders, as it does not assess the domains that are typically impaired. The Montreal Cognitive Assessment has been suggested as the best screening instrument in elderly HIV-infected patients; it is available at no cost at www.mocatest.org.⁵⁸

As HIV-associated neurocognitive disorder is a diagnosis of exclusion, an evaluation for alternative diagnoses such as syphilis, hypothyroidism, and depression is recommended. If an HIV-associated neurocognitive disorder is diagnosed, referral to specialty care should be considered, as interventions such as lumbar puncture to assess cerebrospinal fluid viral escape and changing the antiretroviral regimen to improve central nervous system penetration are possible options under study.

Patients with poorly controlled HIV and a depressed CD4 count are at risk of a number of central nervous system complications in addition to HIV-associated neurocognitive disorders, eg, central nervous system toxoplasmosis, cryptococcal meningitis, progressive multifocal leukoencephalopathy, and primary central nervous system lymphoma. Adherence to an effective antiretroviral regimen is the primary prevention strategy.

Take-home points

• HIV-associated neurocognitive disorders and dementia can occur despite appropriate HIV control and adherence to antiretroviral therapy.
• Adherence to antiretroviral therapy is the primary prevention against most central nervous system complications in HIV infection.

GERIATRIC SYNDROMES

The aging HIV-infected adult may also be at increased risk of geriatric syndromes.

HIV-infected men are 4.5 to 10 times more likely than age-matched controls to be frail

In particular, a frailty-related phenotype of weight loss, exhaustion, slowness, and low physical activity was more common in HIV-infected elderly than in noninfected elderly.⁵⁹ HIV-infected men are 4.5 to 10 times more likely than age-matched controls to be frail, and the likelihood of frailty increases with age, duration of HIV infection, having a CD4 count lower than 350 × 10⁶/L, and having uncontrolled HIV replication.^60,61

Other geriatric syndromes such as falls, urinary incontinence, and functional impairment have been identified in 25% to 56% of older HIV-infected patients.⁶² Indeed, the combination of HIV and older age may adversely affect performance of instrumental activities of daily living.⁶³ Also, as previously mentioned, nondisclosure, fear of HIV-related social stigmatization, and a desire to be self-reliant are all factors that perpetuate the social isolation that is common among the HIV-infected elderly.

For these reasons, a comprehensive approach involving a geriatrician, an infectious disease specialist, and community social workers is needed to manage the care of this aging population.

Take-home point

• Geriatric syndromes have an important impact on health in aging HIV patients.

CANCER SCREENING IN HIV PATIENTS

People with HIV have an elevated risk of cancer. Specifically, compared with the general population, their risk is:

• 3,640 times higher for Kaposi sarcoma
• 77 times higher for non-Hodgkin lymphomas
• 6 times higher for cervical cancer.^64,65

These cancers are considered “AIDS-defining,” and fortunately, the development of effective antiretroviral therapy in the 1990s has led to a marked reduction in their incidence. However, the aging HIV population is now experiencing a rise in the incidence of non–AIDS-defining cancers, such as cancers of the lung, liver, kidney, anus, head and neck, and skin, as well as Hodgkin lymphoma.⁶⁶ Table 2 shows the standardized incidence ratio of selected non–AIDS-defining cancers in HIV-infected patients as reported in several large international studies.^65,67,68 The etiology for the increased risk of non–AIDS-defining cancers in the HIV-infected population is not clear, but possible explanations include the virus itself, antiretroviral therapy, and co-infection with other viruses such as hepatitis B, hepatitis C, and Epstein-Barr virus.

Guidelines for cancer screening vary by organization, and the American Cancer Society, the National Cancer Institute, and the US Preventive Services Task Force do not have formal screening guidelines for the most common non–AIDS-defining cancers. The European AIDS Clinical Society, however, has proposed some screening recommendations for selected malignancies.⁴³

In general, screening recommendations are similar to those for HIV-negative patients. A specific difference for HIV-infected patients is in cervical cancer screening. HIV-infected women should undergo a Papanicolaou smear at 6-month intervals during the first year after diagnosis of HIV infection and, if the results are normal, annually thereafter. There is no consensus as to whether human papillomavirus testing should be performed routinely on HIV-infected women.

At the time of this writing, there are no recommendations for routine screening for anal cancer, although some specialists recommend anal cytologic screening for HIV-positive men and women, and an annual digital anal examination may be useful to detect masses that could be anal cancer.⁶⁹

Take-home points

• The incidence of non–AIDS-defining cancers is rising in the aging HIV population.
• There are currently no formal recommendations for routine screening for anal cancer.

FINAL WORD

Because patients with HIV are living longer as a result of newer effective combination antiretroviral therapies, physicians face a new challenge of managing conditions in these patients that are traditionally associated with aging. Providers will need to improve their understanding of drug-drug interactions and polypharmacy issues and be able to address the complex medical and psychosocial issues in this growing population. As patients with HIV on effective antiretroviral therapy grow older, the burden of comorbid medical disease will continue to increase.

In the 1980s, human immunodeficiency virus (HIV) infection was considered untreatable and predictably lethal. Today, with highly effective antiretroviral therapy, it has become a chronic condition in which patients have a life expectancy comparable to that in the general population.

This change has led to new challenges for primary care physicians, many of whom now find themselves either the sole medical provider for or the comanager of aging HIV-infected patients. Given that about one-fifth of new HIV diagnoses are now in people over the age of 50, it is crucial that primary care providers be able to recognize and diagnose the disease in this population. In addition, they need to effectively manage the polypharmacy and subsequent drug interactions prevalent in older HIV-infected patients. Finally, the clinician must address comorbid diseases common in the elderly, specifically neurologic, cardiovascular, metabolic, and endocrine disorders, as well as performing routine cancer screening.

Take-home point

• As the number of people age 50 and older with HIV infection increases, primary care providers must be able to both recognize and manage the condition.

RISING PREVALENCE OF HIV IN THE ELDERLY

Globally, about 2.5 million people received a new diagnosis of HIV infection in 2011, and about 35 million people worldwide are currently living with it.¹ An estimated 1.1 million Americans are living with HIV, and of these, about 16% do not know they are infected.²

HIV patients who adhere to treatment and achieve a CD4 count above 350 and a low viral load have a normal life expectancy

Antiretroviral therapy has greatly improved the life expectancy of HIV-infected patients, and the number of HIV-infected people over age 50 continues to rise. A successfully treated HIV-positive person with a CD4 count higher than 350 × 10⁶/L and a suppressed viral load now has a normal life expectancy.³ In 2011, nearly 20% of newly diagnosed HIV-infected people in the United States were over age 50, as were nearly 25% of those with a new diagnosis of acquired immune deficiency syndrome (AIDS).⁴ This year (2015), we expect that more than half of all HIV-infected people in the United States will be over age 50.⁵

The rising prevalence of HIV infection in this age group has prompted reevaluation of screening guidelines. The US Preventive Services Task Force recommends screening for HIV in all people ages 15 to 65, and also after age 65 in people at ongoing risk of infection.⁶ The American College of Physicians has suggested that the range for routine HIV screening be expanded to age 75.⁷ The cost-effectiveness of expanded and more frequent HIV testing appears to justify it.⁸

Take-home points

• An HIV-infected patient who is compliant with an appropriate antiretroviral regimen and has a CD4 count higher than 350 × 10⁶/L and a suppressed viral load now has a normal life expectancy.
• Today, nearly 20% of newly diagnosed HIV-infected people and more than 50% of all HIV-infected people in the United States are over the age of 50.
• The age range for routine screening for HIV infection should be expanded.

HIGH-RISK GROUPS AMONG THE ELDERLY

Early in the HIV epidemic, older patients acquired HIV from blood transfusions received because of hemophilia and other disorders. However, this rapidly ceased after blood banks began screening blood products. Today, people over age 50 who acquire HIV have many of the same risk factors as younger people.

Men who have sex with men are the largest subgroup of HIV-infected people in the United States, even among those over age 50. In particular, white men who have sex with men now constitute the largest demographic group among the HIV-infected elderly.⁴

Intravenous drug users make up about 15% of older people with HIV.

Women who have sex with infected men or with men at risk of HIV infection make up the largest group of older women with HIV.⁴

Sex and the older person

Many older HIV-infected people remain sexually active and continue to engage in unprotected sexual intercourse far into advanced age. According to one survey, 53% of Americans ages 65 to 74 are engaging in sexual activity regularly; however, they are not using protective measures with up to 91% of casual partners and 70% of new partners.^9,10 Many widowed and divorced people are dating again, and they may be unfamiliar with condom use or may be reluctant to use condoms because condoms can often make it difficult to maintain an erection.

Drugs for erectile dysfunction are making it easier for the elderly to engage in both vaginal and anal intercourse, but often without a condom.⁹ Older women who no longer worry about getting pregnant may be less likely to insist their partners use a condom and to practice safe sex. In addition, age-related thinning and dryness can cause vaginal tears, increasing the risk of HIV transmission.¹¹

Take-home points

• People older than 50 have risk factors for HIV similar to those in younger people.
• Men who have sex with men compose the largest group of HIV-infected individuals in the elderly population.
• Unprotected sexual intercourse is common in the elderly for several reasons: unfamiliarity with condom use, difficulty maintaining an erection, lack of concern about possible pregnancy, and vaginal thinning and dryness in women.

UNDERDIAGNOSIS AND LATE DIAGNOSIS IN THE ELDERLY

The cumulative number of AIDS cases in adults age 50 and older increased nearly ninefold from 1990 to the end of 2009. Even more worrisome, one-half of HIV-positive adults over age 50 are diagnosed with AIDS simultaneously or within 1 year of their HIV diagnosis.⁴ This late diagnosis—and therefore late initiation of treatment—is associated with poorer health outcomes and more rapid disease progression.¹²

HIV infection in older adults often goes undiagnosed, for several reasons.

Providers may underestimate the risk in this population and therefore may not discuss HIV transmission or perform testing. Despite a US Centers for Disease Control and Prevention recommendation that people ages 13 to 64 be tested at least once, and more often if sexually active, only 35% of adults ages 45 to 64 have ever been tested for HIV infection.¹³

Age greater than 50 has been strongly associated with higher rates of non–AIDS-related cancers and cardiovascular disease

Older patients may not perceive themselves to be at risk of HIV infection because of lack of insight and information about its prevention and transmission. They are also less likely than younger adults to discuss their sexual habits or drug use with providers.¹⁴ In addition, compared with the young sexually active population, very little HIV prevention education is targeted to older people.¹⁵ Social stigmatization is also a concern for many HIV-infected elderly, as a perceived negative reputation within their community may prevent them from seeking care and disclosing their HIV status.

Take-home points

Reasons that HIV infection is underdiagnosed in the elderly include lack of:

• Provider recognition
• Insight and information about HIV prevention and transmission
• HIV-prevention education targeting the elderly
• Disclosure because of the social stigma of HIV infection.

HIV ACCELERATES AGING, AGING REDUCES IMMUNITY

Many HIV-positive people can expect to live as long as people in the general population, but those who are diagnosed late and thus are started on antiretroviral therapy later in the course of their infection have a reduced life expectancy. Longevity depends on both restoring the CD4 count to near-normal and suppressing the viral load to undetectable levels.^3,16 This is especially important for older adults, as HIV may accelerate aging, and aging itself may speed the progression of HIV disease, so that therapy may result in delayed or only partial restoration of immunity.

Older age at the time of HIV infection is a strong predictor of accelerated HIV disease progression in the absence of therapy.¹⁷ Left untreated, older patients with HIV lose CD4 cells and progress to AIDS and death faster than younger patients. The deleterious effects of chronic immune activation in the course of HIV infection, combined with the immune senescence of aging, are thought to promote this accelerated course.¹⁸

Recent data indicate that starting antiretroviral therapy early can help prevent the CD4-cell impairment that occurs with aging.¹⁹ However, in adults over age 50, the capacity to restore the CD4 count with antiretroviral therapy apears to be reduced, despite demonstrated viral load suppression and better adherence.²⁰ Although mean adherence rates appear higher in older HIV-infected patients, they are worse in those with neurocognitive impairment, highlighting the importance of evaluating neurocognition in this population.²¹

Decreased immune recovery and the subsequent increased risk of serious AIDS events are factors that now favor starting antiretroviral therapy in all HIV patients over age 50, regardless of CD4 count.

Take-home points

• Without treatment, HIV infection in older patients progresses more rapidly to AIDS and death than in younger patients.
• HIV-positive people over age 50 who have never received antiretroviral therapy should be strongly considered for it, regardless of the CD4 count.

SO MANY DRUGS, SO MANY INTERACTIONS

Since HIV patients are now living longer thanks to antiretroviral therapy, they are now experiencing more disease- and treatment-related problems. This has led to an increased likelihood of polypharmacy, defined here as the use of six or more medications.

In general, polypharmacy in the elderly is associated with adverse drug events, drug interactions, inappropriate medication use, delirium, falls, fractures, and poor medication adherence.^22,23 But it becomes even more of a problem in HIV-infected elderly patients, as various drug interactions can alter the effectiveness of the antiretroviral regimen and can result in drug toxicity.

The most common classes of medications used in the elderly are antihypertensives, lipid-lowering agents, antiplatelet medications, antidepressants, anxiolytics, sedatives, and analgesics, and many of these have notable interactions with current antiretroviral regimens.^24,25 Most medications, including antiretrovirals, are cleared by the liver or kidneys, and the function of these organs often decreases with age, resulting in impaired elimination and in drug accumulation.

Information on drug interactions is readily available from the US Department of Health and Human Services,²⁶ drug interaction databases,^27,28 and drug interaction software. The combination of antiretroviral therapy and preexisting polypharmacy significantly increases the risk of serious interactions, which can lead to drug toxicity, poorer adherence with antiretroviral therapy, loss of efficacy of the coadministered medication, or resurgence of HIV infection due to drug-drug interactions affecting the metabolism and ultimate efficacy of the antiretroviral therapy. An increased awareness of common drug-drug interactions can prevent coadministration of potentially harmful medications in elderly HIV patients.

Important interactions between antiretroviral drugs and other drug classes are summarized in Table 1.^25–28 Most notably:

• Simvastatin and lovastatin are contraindicated with any protease inhibitor.
• Proton pump inhibitors are not recommended for patients taking ritonavir-boosted atazanavir. If a proton pump inhibitor is necessary, the daily dose should not exceed 20 mg of omeprazole or its equivalent in patients who have never taken a protease inhibitor, and it should be taken 12 hours before boosted atazanavir.²⁶
• Corticosteroids, whether systemic, inhaled, or intranasal (eg, fluticasone, budesonide), should be avoided in combination with any protease inhibitor, as they can cause iatrogenic Cushing syndrome and also pose the risk of adrenal crisis during acute illness.²⁷

Take-home points

• In cases of preexisting polypharmacy, antiretroviral therapy can lead to significant drug toxicity, poor adherence to medications, and resurgence of HIV infection.
• Increased provider awareness of common drug-drug interactions can prevent the prescribing of potentially harmful drug combinations to HIV-infected elderly patients.

COMORBIDITIES

In recent years, more than half of the deaths in HIV patients on antiretroviral therapy have been from noninfectious comorbidities such as cardiovascular disease, bone disease, and renal failure, which often coexist and are associated with advanced age.²⁹ In fact, both older age and each additional year of antiretroviral therapy are independent predictors of polypathology (simultaneous occurrence of two or more defined diseases).³⁰ The Antiretroviral Therapy Cohort Collaboration found that age greater than 50 was strongly associated with increasing rates of non–AIDS-related malignancy and cardiovascular disease.³¹

CARDIOVASCULAR DISEASE

With the increasing life expectancy of HIV-infected adults on antiretroviral therapy, cardiovascular disease has become an important concern. HIV-infected adults appear to have a significantly greater risk of myocardial infarction and coronary artery disease than age-matched HIV-negative individuals.³² Strikingly, being older than 50 itself increases the risk of hospitalization for cardiovascular disease fivefold (incidence rate ratio 5.01, 95% confidence interval 3.41–7.38).³³ In addition, HIV infection is associated with a risk of acute myocardial infarction 50% higher than that explained by recognized risk factors.³⁴

This high prevalence of coronary artery disease is likely from a combination of factors, including increasing age and the chronic inflammation and immune activation associated with HIV infection.³⁵ An association between untreated HIV disease and markers of risk for cardiovascular disease has been identified.^36,37

HIV is associated with a 50% higher risk of acute myocardial infarction beyond traditional risk factors

In addition, antiretroviral therapy is associated with dyslipidemia, which is most pronounced with protease inhibitor regimens. Whether specific lipid changes associated with individual antiretroviral drugs affect cardiovascular risk remains uncertain. In the Data Collection on Adverse Events of Anti-HIV Drugs studies,³⁸ only cumulative exposure to indinavir, lopinavir-ritonavir, and didanosine was associated with an increased risk of myocardial infarction.³⁸

Traditional risk factors such as obesity, tobacco use, and genetic predisposition also apply to HIV-infected people.³⁹ In fact, the prevalence of traditional risk factors such as smoking and dyslipidemia is generally higher in HIV-infected people than in the general population, although this situation may be improving.⁴⁰

Science needs to elucidate the relationship between traditional and nontraditional risk factors for cardiovascular disease in older HIV-infected adults. In the meantime, older patients with HIV require aggressive management of modifiable risk factors.

Tools for assessing cardiovascular risk include the Framingham risk score⁴¹ and the Data Collection on Adverse Events of Anti-HIV Drugs 5-year risk calculator.⁴² The European AIDS Clinical Society guidelines recommend considering changing the antiretroviral regimen if the patient’s 10-year risk of cardiovascular disease is more than 20%.⁴³ Recommended strategies for reducing cardiovascular risk in elderly patients with HIV infection include counseling about smoking cessation and weight loss at every clinic visit and optimally controlling dyslipidemia and hypertension using nationally accepted standardized guidelines.⁴⁴

Take-home points

• HIV infection is associated with a 50% higher risk of acute myocardial infarction beyond that explained by traditional risk factors.
• Chronic inflammation, immune activation, and dyslipidemia associated with antiretroviral therapy all contribute to cardiovascular disease in HIV-infected patients.
• HIV-infected elderly patients require aggressive management of modifiable risk factors for cardiovascular disease.

ENDOCRINE DISEASE

Diabetes mellitus

The estimated prevalence of diabetes mellitus is 3% in HIV-infected people who have never received antiretroviral therapy, but glucose intolerance increases to the range of 10% to 25% in those who have started it.⁴⁵ Glucose disorders are associated with traditional risk factors as well as with HIV-associated factors such as lipodystrophy and antiretroviral therapy, specifically long-term use of protease inhibitors.⁴⁶ Although increasing age and obesity clearly play a role in the development of diabetes mellitus in this population, HIV-specific factors may also allow diabetes to develop at a lower level of adiposity than in people without HIV infection.⁴⁷

Strategies for preventing type 2 diabetes mellitus in HIV-infected patients focus on avoiding excessive weight gain, especially after starting antiretroviral therapy; regularly screening for diabetes using hemoglobin A_1c, both before and after starting antiretroviral therapy; and continuing to check hemoglobin A_1c every 6 months. The target hemoglobin A_1c should be less than 7.0%. This threshold should be increased to 8% in frail elderly adults if their anticipated life expectancy is less than 5 years, given their higher risk of hypoglycemia, polypharmacy, and drug interactions.⁴⁸ In addition, as in HIV-negative patients, diabetes screening should be performed if systolic blood pressure exceeds 135/80 mm Hg.

Insulin sensitizers such as metformin and thiazolidinediones should be considered for treating diabetes in HIV-infected patients if no contraindications exist. Consideration may also be given to switching the antiretroviral regimen from a protease inhibitor-based regimen to a nonnucleoside reverse transcriptase inhibitor-based regimen.⁴⁸

Take-home points

• Glucose intolerance has been associated with HIV-specific factors, including lipodystrophy and antiretroviral therapy.
• Avoiding excessive weight gain, use of insulin-sensitizing medications, and alteration in antiretroviral regimens should be considered for the treatment of diabetes mellitus in HIV infection.

Osteoporosis

Osteoporotic bone disease disproportionately affects patients with advanced HIV infection compared with patients of similar age.⁴⁹ Bone mineral density is lower and the fracture rate is higher in HIV-infected individuals.

The pathogenesis of bone disease appears to be multifactorial. Traditional risk factors include hypogonadism, smoking, alcohol use, and low body weight, while HIV-related risk factors include chronic immune activation and antiretroviral therapy.⁵⁰

Several antiretroviral regimens have been linked to clinically significant bone loss, including both tenofovir-based and protease inhibitor-based regimens.⁵¹ Most studies have shown that bone mineral density decreases by 2% to 6% in the first 2 years after starting these regimens⁵²; however, long-term effects on bone loss are unknown.

Questions remain. For example, what are the exact mechanisms that lead to the acute decrease in bone mineral density after starting antiretroviral therapy? And why is vitamin D deficiency is so prevalent in HIV infection, with low vitamin D levels seen in up to 60% to 75% of elderly HIV-infected patients?⁵³

Osteoporosis and vitamin D deficiency appear to be more prevalent with HIV infection

Both the Work Group for the HIV and Aging Consensus Project⁵⁴ and the European AIDS Clinical Society⁴³ recommend screening for and treating causes of secondary low bone mineral density in HIV-infected men over age 50 and postmenopausal HIV-infected women. These causes include vitamin D deficiency. As of 2013, the National Osteoporosis Foundation guidelines include HIV infection and antiretroviral therapy as osteoporosis risk factors that should trigger screening for low bone mineral density with dual-energy x-ray absorptiometry (DXA).⁵⁵

As in the general population, the preferred treatment for low bone mineral density in people with HIV is a bisphosphonate, in addition to ensuring adequate calcium and vitamin D intake. It is important to repeat DXA imaging every 2 years and to reassess the need for continued bisphosphonate therapy after 3 to 5 years because of a possible increased risk of fracture with prolonged use.

Take-home points

• Osteoporosis and vitamin D deficiency both appear to be more prevalent with HIV infection.
• HIV infection and antiretroviral therapy are risk factors that should prompt DXA screening to evaluate for osteoporosis.

NEUROCOGNITIVE DISORDERS

HIV-associated neurocognitive disorders are common, with an estimated 50% of HIV-infected patients experiencing some degree of cognitive loss and some progressing to dementia.⁵⁶ Unfortunately, studies suggest that cognitive disorders can occur despite good HIV control with antiretroviral therapy, with one report demonstrating that 84% of patients with cognitive complaints and 64% without complaints were affected by an HIV-associated neurocognitive disorder.⁵⁷

HIV-associated dementia is often subcortical, with fluctuating symptoms such as psychomotor retardation, difficulty multitasking, and apathy. In contrast to dementia syndromes such as Alzheimer disease, relentless progression is less common in HIV-infected patients who receive antiretroviral therapy.

The Mini-Mental State Examination should not be used to screen for HIV-associated neurocognitive disorders, as it does not assess the domains that are typically impaired. The Montreal Cognitive Assessment has been suggested as the best screening instrument in elderly HIV-infected patients; it is available at no cost at www.mocatest.org.⁵⁸

As HIV-associated neurocognitive disorder is a diagnosis of exclusion, an evaluation for alternative diagnoses such as syphilis, hypothyroidism, and depression is recommended. If an HIV-associated neurocognitive disorder is diagnosed, referral to specialty care should be considered, as interventions such as lumbar puncture to assess cerebrospinal fluid viral escape and changing the antiretroviral regimen to improve central nervous system penetration are possible options under study.

Patients with poorly controlled HIV and a depressed CD4 count are at risk of a number of central nervous system complications in addition to HIV-associated neurocognitive disorders, eg, central nervous system toxoplasmosis, cryptococcal meningitis, progressive multifocal leukoencephalopathy, and primary central nervous system lymphoma. Adherence to an effective antiretroviral regimen is the primary prevention strategy.

Take-home points

• HIV-associated neurocognitive disorders and dementia can occur despite appropriate HIV control and adherence to antiretroviral therapy.
• Adherence to antiretroviral therapy is the primary prevention against most central nervous system complications in HIV infection.

GERIATRIC SYNDROMES

The aging HIV-infected adult may also be at increased risk of geriatric syndromes.

HIV-infected men are 4.5 to 10 times more likely than age-matched controls to be frail

In particular, a frailty-related phenotype of weight loss, exhaustion, slowness, and low physical activity was more common in HIV-infected elderly than in noninfected elderly.⁵⁹ HIV-infected men are 4.5 to 10 times more likely than age-matched controls to be frail, and the likelihood of frailty increases with age, duration of HIV infection, having a CD4 count lower than 350 × 10⁶/L, and having uncontrolled HIV replication.^60,61

Other geriatric syndromes such as falls, urinary incontinence, and functional impairment have been identified in 25% to 56% of older HIV-infected patients.⁶² Indeed, the combination of HIV and older age may adversely affect performance of instrumental activities of daily living.⁶³ Also, as previously mentioned, nondisclosure, fear of HIV-related social stigmatization, and a desire to be self-reliant are all factors that perpetuate the social isolation that is common among the HIV-infected elderly.

For these reasons, a comprehensive approach involving a geriatrician, an infectious disease specialist, and community social workers is needed to manage the care of this aging population.

Take-home point

• Geriatric syndromes have an important impact on health in aging HIV patients.

CANCER SCREENING IN HIV PATIENTS

People with HIV have an elevated risk of cancer. Specifically, compared with the general population, their risk is:

• 3,640 times higher for Kaposi sarcoma
• 77 times higher for non-Hodgkin lymphomas
• 6 times higher for cervical cancer.^64,65

These cancers are considered “AIDS-defining,” and fortunately, the development of effective antiretroviral therapy in the 1990s has led to a marked reduction in their incidence. However, the aging HIV population is now experiencing a rise in the incidence of non–AIDS-defining cancers, such as cancers of the lung, liver, kidney, anus, head and neck, and skin, as well as Hodgkin lymphoma.⁶⁶ Table 2 shows the standardized incidence ratio of selected non–AIDS-defining cancers in HIV-infected patients as reported in several large international studies.^65,67,68 The etiology for the increased risk of non–AIDS-defining cancers in the HIV-infected population is not clear, but possible explanations include the virus itself, antiretroviral therapy, and co-infection with other viruses such as hepatitis B, hepatitis C, and Epstein-Barr virus.

Guidelines for cancer screening vary by organization, and the American Cancer Society, the National Cancer Institute, and the US Preventive Services Task Force do not have formal screening guidelines for the most common non–AIDS-defining cancers. The European AIDS Clinical Society, however, has proposed some screening recommendations for selected malignancies.⁴³

In general, screening recommendations are similar to those for HIV-negative patients. A specific difference for HIV-infected patients is in cervical cancer screening. HIV-infected women should undergo a Papanicolaou smear at 6-month intervals during the first year after diagnosis of HIV infection and, if the results are normal, annually thereafter. There is no consensus as to whether human papillomavirus testing should be performed routinely on HIV-infected women.

At the time of this writing, there are no recommendations for routine screening for anal cancer, although some specialists recommend anal cytologic screening for HIV-positive men and women, and an annual digital anal examination may be useful to detect masses that could be anal cancer.⁶⁹

Take-home points

• The incidence of non–AIDS-defining cancers is rising in the aging HIV population.
• There are currently no formal recommendations for routine screening for anal cancer.

FINAL WORD

Because patients with HIV are living longer as a result of newer effective combination antiretroviral therapies, physicians face a new challenge of managing conditions in these patients that are traditionally associated with aging. Providers will need to improve their understanding of drug-drug interactions and polypharmacy issues and be able to address the complex medical and psychosocial issues in this growing population. As patients with HIV on effective antiretroviral therapy grow older, the burden of comorbid medical disease will continue to increase.

With the growing use of marijuana, reports have appeared of a newly recognized condition in long-term heavy users termed cannabinoid hyperemesis syndrome.¹

This syndrome is interesting for at least two reasons. First, paradoxically, marijuana appears to have an emetic effect with chronic use, whereas it usually has the opposite effect and is used as an antiemetic in patients undergoing chemotherapy. Second, patients develop a compulsion to bathe or shower in extremely hot water to relieve the symptoms.

In this article, we review the pathophysiology, clinical presentation, diagnosis, and management of this emerging condition.

MARIJUANA USE ON THE RISE

Marijuana is the most widely used illicit drug worldwide. Although statistics on its use vary, a report from the Pew Research Center² stated that 49% of Americans say they have tried it. Several states now allow the use of marijuana for medicinal purposes, and Colorado and Washington have legalized it for recreational use. This marks a major turning point and may accelerate the slow-growing acceptance of marijuana use in the United States.

Marijuana has been used to treat HIV-associated anorexia and wasting, convulsions, glaucoma, headache, and chemotherapy-induced nausea and vomiting.^3–5

Cannabinoid hyperemesis syndrome was first described in 2004 in South Australia.¹ Since its recognition, an increasing number of cases have been identified worldwide. However, there are still no population-based studies to estimate its exact prevalence.

THC PREVENTS VOMITING—AND CAUSES IT

Delta-9-tetrahydrocannabinol (THC) is the principal psychoactive component in marijuana.^6,7 There are two types of cannabinoid receptors in humans: CB1 and CB2. Both are found in the central nervous system and autonomic nervous system. Activation of CB1 receptors is responsible for the psychoactive effects of cannabinoids such as altered consciousness, euphoria, relaxation, perceptual disturbances, intensified sensory experiences, cognitive impairment, and increased reaction time. The physiologic role of CB2 is not known.

THC as an antiemetic

The antiemetic property of THC is not well understood but has been linked to activation of CB1 receptors found on the enteric plexus, presynaptic parasympathetic system, and central nervous system, particularly the cerebellum, hypothalamus, and vomiting center in the medulla.^1,8–12 Stimulation and blockade of CB1 receptors can inhibit and induce vomiting in a dose-dependent manner, implicating endogenous cannabinoids in emetic circuits.¹²

THC as a proemetic

The mechanism of the paradoxical hyperemetic effect of THC is unknown, but several concepts have been proposed.

Chronic cannabis use can lead to down-regulation of CB1 receptors.¹³ Simonetto et al¹⁰ suggested that the central effects of long-term cannabis use on the hypothalamic-pituitary-adrenal axis may play a central role in the development of hyperemesis.¹⁰

Cannabinoids have a long half-life and are lipophilic.¹ When used infrequently, they prevent vomiting. But with chronic use, high concentrations of THC can accumulate in the body, including cerebral fat, and can cause severe nausea and vomiting.^8,9 This paradoxic hyperemesis was observed in people using intravenous crude marijuana extract.⁷ The same response was also noted in ferrets injected with 2-arachidonoylglycerol, a potent cannabinoid agonist.¹¹

Patients who experience hyperemesis from chronic cannabis use may also have a genetic variation in their hepatic drug-transforming enzymes that results in excessive levels of cannabis metabolites that promote emesis.^1,14

Delayed gastric emptying has also been linked to the proemetic effect of THC. However, this association became controversial when a large case series study showed that only 30% of patients with cannabinoid hyperemesis syndrome had delayed emptying on gastric scintigraphy.¹⁰

It is also possible that excessive stimulation of cannabinoid receptors in the gut can cause diffuse splanchnic vasodilation and contribute to the abdominal pain.¹³

DIAGNOSING CANNABINOID HYPEREMESIS SYNDROME

Cannabinoid hyperemesis syndrome is a clinical diagnosis typically seen in young patients (under age 50) with a long history of marijuana use. They present with severe, cyclic nausea and vomiting and admit to compulsively taking extremely hot showers or baths. Most patients report using marijuana for more than a year before developing episodes of severe vomiting. However, one study found that as many as 32% of patients had used it less than 1 year before experiencing symptoms.¹⁰

Other associated nonspecific symptoms are diaphoresis, bloating, abdominal discomfort, flushing, and weight loss. Symptoms are relieved with long, hot showers or baths and cessation of marijuana use. Taking a complete history is key to making the diagnosis.

In 2004, Allen et al¹ first defined cannabinoid hyperemesis as excessive marijuana use associated with cyclical vomiting and abdominal pain.¹ In 2012, Simonetto et al¹⁰ proposed diagnostic criteria (Table 1). Although not yet validated, these criteria are based on the largest series of cases of cannabinoid hyperemesis syndrome to date (98 patients).¹⁰

THE THREE PHASES OF CANNABINOID HYPEREMESIS

The clinical presentation of cannabinoid hyperemesis syndrome can be divided into three phases: prodromal, vomiting, and resolution.

Prodromal phase

During this phase, patients often appear anxious and agitated and display a spectrum of autonomic symptoms such as sweating, flushing, and constantly sipping water due to thirst. They may sometimes have abdominal pain that is usually epigastric but may also be diffuse. Their symptoms are associated with severe nausea, usually early in the morning or when they see or smell food. Appetite and eating patterns remain normal. Compulsive hot bathing or showering is minimal at this phase.

Vomiting phase

In this next phase, patients experience incapacitating nausea and vomiting that may occur without warning and are resistant to conventional antiemetics such as ondansetron and promethazine.¹⁴ However, patients eventually learn that hot baths or showers relieve the symptoms, and this behavior eventually becomes a compulsion. The higher the temperature of the water, the better the effect on symptoms.¹ Low-grade pyrexia, excessive thirst, orthostasis, abdominal tenderness, weight loss, and sometimes even superficial skin burns have been reported.^1,9,15–18

Recovery phase

During the final phase of cannabinoid hyperemesis syndrome, most patients experience marked resolution of symptoms after 24 to 48 hours of conservative management (bowel rest until symptoms resolve, slowly advancing diet as tolerated, intravenous fluids, and electrolyte monitoring and repletion as necessary), and most importantly, cessation of cannabis use. However, the time from cessation of marijuana use to resolution of symptoms may be as long as 1 week to 1 month.^1,10,14 Patients begin to resume their normal diet and daily activities. The bathing-showering compulsion subsides, and patients regain lost weight after 3 to 6 months.¹

In all case series and reports, resumption of cannabis use causes the symptoms to recur. This recurrence is compelling evidence that cannabis is the cause of the hyperemesis and should be part of the essential criteria for the diagnosis of cannabinoid hyperemesis syndrome.

WHY COMPULSIVE HOT BATHING?

The mechanism behind this unique characteristic of cannabinoid hyperemesis syndrome is not known. Several theories have been suggested, but no study has identified the exact explanation for this phenomenon.^{1,9,10,13–15,17–31}

One suggested mechanism is a response by the thermoregulatory center of the brain to the dose-dependent hypothermic effects of THC, or even a direct effect of CB1 receptor activation in the hypothalamus.⁹ Cannabis toxicity could disrupt the equilibrium of satiety, thirst, digestive, and thermoregulatory systems of the hypothalamus, and this interference could resolve with hot bathing.¹

The so-called “cutaneous steal” syndrome has also been proposed, in which cutaneous vasodilation caused by hot water decreases the blood volume available for the splanchnic circulation thought to be responsible for the abdominal pain and vomiting.¹³ The compulsive hot bathing may also be a response by the brain to the anxiety or psychological stress induced by severe nausea and vomiting.¹⁴

DIFFERENTIAL DIAGNOSIS

The differential diagnosis of cannabinoid hyperemesis syndrome includes mainly cyclic vomiting syndrome and psychogenic vomiting. A careful history is useful, as is ruling out medication-induced reactions, toxins, pregnancy, and gastrointestinal, neurologic, metabolic, and endocrine causes. All three of these vomiting syndromes can present with a cyclic pattern of nausea and vomiting. Cannabis use is common in all three and so is not helpful in differentiating them. But the characteristic compulsive hot bathing and showering is unique and pathognomonic of cannabinoid hyperemesis syndrome.³²

Endoscopic examination may reveal esophagitis and gastritis from severe bouts of retching.²⁶

Cyclic vomiting syndrome

The Rome III criteria for the diagnosis of cyclic vomiting syndrome include three or more stereotypic episodes of acute-onset nausea and vomiting lasting less than 1 week, alternating with intervals of completely normal health. The criteria should be fulfilled for the previous 3 months with symptom onset at least 6 months before diagnosis.³³

In a series of 17 patients with adult-onset cyclic vomiting syndrome,¹⁸ the average age at onset was 30, and 13 (76%) of the patients were women. Fifteen (88%) of the patients experienced a prodrome or aura of abdominal pain or headache, and in this group, a trigger such as emotional stress and infection could also be identified in 9 (60%).

Unlike in cannabinoid hyperemesis syndrome, most patients with cyclic vomiting syndrome have a family history of migraine headache, and the prevalence of psychological stressors is high.³¹ Also, patients with cannabinoid hyperemesis syndrome do not respond to medications that usually abort migraine episodes,¹⁵ whereas patients with cyclic vomiting syndrome, especially those who have a family history of migraines, may respond to antimigraine medications such as triptans. There is evidence of clinical psychological overlap between cyclic vomiting syndrome, abdominal migraine, and migraine headaches. Some authors recommend antimigraine therapy even in the absence of a family or personal history of migraine if, after a careful history and physical examination, the diagnosis of cyclic vomiting syndrome seems likely. Moreover, nonmedical management such as sleep, dark rooms, and quiet environment are not as effective in cannabinoid hyperemesis syndrome as they are in cyclic vomiting syndrome.¹⁸

Psychogenic vomiting

Psychogenic vomiting is classically defined as vomiting caused by psychological mechanisms without any obvious organic cause.¹³ It occurs most commonly in patients with major depressive disorder or conversion disorder.³⁴ The mechanism appears to be a combination of past organic or gastrointestinal functional abnormalities and emotional problems, and multiple patterns of vomiting can occur. Most of these patients can be treated with behavioral therapy, antidepressant drug therapy, and supportive psychotherapy.^34,35

ASKING A SERIES OF QUESTIONS

Most patients with cannabinoid hyperemesis syndrome have a history of frequent visits to emergency departments or clinics for persistent nausea and vomiting, and they may have undergone extensive diagnostic workups to exclude structural, inflammatory, infectious, and functional diseases of the bowel.^23,24

To prevent unnecessary testing and use of healthcare resources, Wallace et al³² proposed an algorithm to help guide clinicians in diagnosing and treating patients with suspected cannabinoid hyperemesis syndrome. A patient presenting with severe nausea and vomiting should prompt a series of questions:

Do the signs and symptoms suggest a severe underlying medical cause? If so, this should be pursued.

Do symptoms improve while taking a hot shower or bath? If not, pursue an appropriate diagnostic evaluation and treatment for conditions other than cannabinoid hyperemesis syndrome.

Is the bathing compulsive? If not, consider other diagnoses, but remain suspicious about cannabinoid hyperemesis syndrome.

Does the patient currently use cannabis daily or almost daily, and has the patient done so for at least the past year? If the patient denies using cannabis, a urine drug screen for THC may be useful. If the patient admits to use, a presumptive diagnosis of cannabinoid hyperemesis syndrome can be made.

Does the patient have signs or symptoms of volume depletion, or is the patient unable to tolerate oral hydration? Encourage oral hydration or provide intravenous hydration, and provide cannabis cessation counseling.

Do the symptoms improve? If yes, great! Provide cessation counseling, resources, and follow-up. If not:

Is the patient still using cannabis? If not, it is time to rethink the diagnosis.

Treatment in the acute setting is supportive and includes intravenous hydration and correction of electrolytes. Conventional antiemetics such as ondansetron, metoclopramide, prochlorperazine, and promethazine have not been effective in relieving hyperemesis.^9,12,14 This implies that the mechanism of emesis likely does not involve dopaminergic and serotonin pathways in the central and autonomic nervous systems.

Cessation of cannabis use is key for long-term resolution of symptoms. Efforts should be made to provide counseling and encourage patients to stop using the drug entirely (Figure 1).

SOMETHING TO THINK ABOUT

With the high prevalence of chronic cannabis abuse and the recent legalization of recreational marijuana use, we will all likely encounter a patient with cannabinoid hyperemesis. With adequate knowledge of this phenomenon, we can avoid unnecessary workups and inappropriate medical and surgical treatment in patients presenting with recurrent vomiting of unknown cause. The diagnosis can easily be made by simply asking for a history of chronic marijuana use and symptoms related to cannabinoid hyperemesis syndrome, such as relief of symptoms with hot baths or showers and with marijuana cessation.

Conservative management and fluid resuscitation is important in the acute setting, but cessation of marijuana use and follow-up counseling are the key components for treating patients with cannabinoid hyperemesis syndrome and for preventing recurrence.

With the growing use of marijuana, reports have appeared of a newly recognized condition in long-term heavy users termed cannabinoid hyperemesis syndrome.¹

This syndrome is interesting for at least two reasons. First, paradoxically, marijuana appears to have an emetic effect with chronic use, whereas it usually has the opposite effect and is used as an antiemetic in patients undergoing chemotherapy. Second, patients develop a compulsion to bathe or shower in extremely hot water to relieve the symptoms.

In this article, we review the pathophysiology, clinical presentation, diagnosis, and management of this emerging condition.

MARIJUANA USE ON THE RISE

Marijuana is the most widely used illicit drug worldwide. Although statistics on its use vary, a report from the Pew Research Center² stated that 49% of Americans say they have tried it. Several states now allow the use of marijuana for medicinal purposes, and Colorado and Washington have legalized it for recreational use. This marks a major turning point and may accelerate the slow-growing acceptance of marijuana use in the United States.

Marijuana has been used to treat HIV-associated anorexia and wasting, convulsions, glaucoma, headache, and chemotherapy-induced nausea and vomiting.^3–5

Cannabinoid hyperemesis syndrome was first described in 2004 in South Australia.¹ Since its recognition, an increasing number of cases have been identified worldwide. However, there are still no population-based studies to estimate its exact prevalence.

THC PREVENTS VOMITING—AND CAUSES IT

Delta-9-tetrahydrocannabinol (THC) is the principal psychoactive component in marijuana.^6,7 There are two types of cannabinoid receptors in humans: CB1 and CB2. Both are found in the central nervous system and autonomic nervous system. Activation of CB1 receptors is responsible for the psychoactive effects of cannabinoids such as altered consciousness, euphoria, relaxation, perceptual disturbances, intensified sensory experiences, cognitive impairment, and increased reaction time. The physiologic role of CB2 is not known.

THC as an antiemetic

The antiemetic property of THC is not well understood but has been linked to activation of CB1 receptors found on the enteric plexus, presynaptic parasympathetic system, and central nervous system, particularly the cerebellum, hypothalamus, and vomiting center in the medulla.^1,8–12 Stimulation and blockade of CB1 receptors can inhibit and induce vomiting in a dose-dependent manner, implicating endogenous cannabinoids in emetic circuits.¹²

THC as a proemetic

The mechanism of the paradoxical hyperemetic effect of THC is unknown, but several concepts have been proposed.

Chronic cannabis use can lead to down-regulation of CB1 receptors.¹³ Simonetto et al¹⁰ suggested that the central effects of long-term cannabis use on the hypothalamic-pituitary-adrenal axis may play a central role in the development of hyperemesis.¹⁰

Cannabinoids have a long half-life and are lipophilic.¹ When used infrequently, they prevent vomiting. But with chronic use, high concentrations of THC can accumulate in the body, including cerebral fat, and can cause severe nausea and vomiting.^8,9 This paradoxic hyperemesis was observed in people using intravenous crude marijuana extract.⁷ The same response was also noted in ferrets injected with 2-arachidonoylglycerol, a potent cannabinoid agonist.¹¹

Patients who experience hyperemesis from chronic cannabis use may also have a genetic variation in their hepatic drug-transforming enzymes that results in excessive levels of cannabis metabolites that promote emesis.^1,14

Delayed gastric emptying has also been linked to the proemetic effect of THC. However, this association became controversial when a large case series study showed that only 30% of patients with cannabinoid hyperemesis syndrome had delayed emptying on gastric scintigraphy.¹⁰

It is also possible that excessive stimulation of cannabinoid receptors in the gut can cause diffuse splanchnic vasodilation and contribute to the abdominal pain.¹³

DIAGNOSING CANNABINOID HYPEREMESIS SYNDROME

Cannabinoid hyperemesis syndrome is a clinical diagnosis typically seen in young patients (under age 50) with a long history of marijuana use. They present with severe, cyclic nausea and vomiting and admit to compulsively taking extremely hot showers or baths. Most patients report using marijuana for more than a year before developing episodes of severe vomiting. However, one study found that as many as 32% of patients had used it less than 1 year before experiencing symptoms.¹⁰

Other associated nonspecific symptoms are diaphoresis, bloating, abdominal discomfort, flushing, and weight loss. Symptoms are relieved with long, hot showers or baths and cessation of marijuana use. Taking a complete history is key to making the diagnosis.

In 2004, Allen et al¹ first defined cannabinoid hyperemesis as excessive marijuana use associated with cyclical vomiting and abdominal pain.¹ In 2012, Simonetto et al¹⁰ proposed diagnostic criteria (Table 1). Although not yet validated, these criteria are based on the largest series of cases of cannabinoid hyperemesis syndrome to date (98 patients).¹⁰

THE THREE PHASES OF CANNABINOID HYPEREMESIS

The clinical presentation of cannabinoid hyperemesis syndrome can be divided into three phases: prodromal, vomiting, and resolution.

Prodromal phase

During this phase, patients often appear anxious and agitated and display a spectrum of autonomic symptoms such as sweating, flushing, and constantly sipping water due to thirst. They may sometimes have abdominal pain that is usually epigastric but may also be diffuse. Their symptoms are associated with severe nausea, usually early in the morning or when they see or smell food. Appetite and eating patterns remain normal. Compulsive hot bathing or showering is minimal at this phase.

Vomiting phase

In this next phase, patients experience incapacitating nausea and vomiting that may occur without warning and are resistant to conventional antiemetics such as ondansetron and promethazine.¹⁴ However, patients eventually learn that hot baths or showers relieve the symptoms, and this behavior eventually becomes a compulsion. The higher the temperature of the water, the better the effect on symptoms.¹ Low-grade pyrexia, excessive thirst, orthostasis, abdominal tenderness, weight loss, and sometimes even superficial skin burns have been reported.^1,9,15–18

Recovery phase

During the final phase of cannabinoid hyperemesis syndrome, most patients experience marked resolution of symptoms after 24 to 48 hours of conservative management (bowel rest until symptoms resolve, slowly advancing diet as tolerated, intravenous fluids, and electrolyte monitoring and repletion as necessary), and most importantly, cessation of cannabis use. However, the time from cessation of marijuana use to resolution of symptoms may be as long as 1 week to 1 month.^1,10,14 Patients begin to resume their normal diet and daily activities. The bathing-showering compulsion subsides, and patients regain lost weight after 3 to 6 months.¹

In all case series and reports, resumption of cannabis use causes the symptoms to recur. This recurrence is compelling evidence that cannabis is the cause of the hyperemesis and should be part of the essential criteria for the diagnosis of cannabinoid hyperemesis syndrome.

WHY COMPULSIVE HOT BATHING?

The mechanism behind this unique characteristic of cannabinoid hyperemesis syndrome is not known. Several theories have been suggested, but no study has identified the exact explanation for this phenomenon.^{1,9,10,13–15,17–31}

One suggested mechanism is a response by the thermoregulatory center of the brain to the dose-dependent hypothermic effects of THC, or even a direct effect of CB1 receptor activation in the hypothalamus.⁹ Cannabis toxicity could disrupt the equilibrium of satiety, thirst, digestive, and thermoregulatory systems of the hypothalamus, and this interference could resolve with hot bathing.¹

The so-called “cutaneous steal” syndrome has also been proposed, in which cutaneous vasodilation caused by hot water decreases the blood volume available for the splanchnic circulation thought to be responsible for the abdominal pain and vomiting.¹³ The compulsive hot bathing may also be a response by the brain to the anxiety or psychological stress induced by severe nausea and vomiting.¹⁴

DIFFERENTIAL DIAGNOSIS

The differential diagnosis of cannabinoid hyperemesis syndrome includes mainly cyclic vomiting syndrome and psychogenic vomiting. A careful history is useful, as is ruling out medication-induced reactions, toxins, pregnancy, and gastrointestinal, neurologic, metabolic, and endocrine causes. All three of these vomiting syndromes can present with a cyclic pattern of nausea and vomiting. Cannabis use is common in all three and so is not helpful in differentiating them. But the characteristic compulsive hot bathing and showering is unique and pathognomonic of cannabinoid hyperemesis syndrome.³²

Endoscopic examination may reveal esophagitis and gastritis from severe bouts of retching.²⁶

Cyclic vomiting syndrome

The Rome III criteria for the diagnosis of cyclic vomiting syndrome include three or more stereotypic episodes of acute-onset nausea and vomiting lasting less than 1 week, alternating with intervals of completely normal health. The criteria should be fulfilled for the previous 3 months with symptom onset at least 6 months before diagnosis.³³

In a series of 17 patients with adult-onset cyclic vomiting syndrome,¹⁸ the average age at onset was 30, and 13 (76%) of the patients were women. Fifteen (88%) of the patients experienced a prodrome or aura of abdominal pain or headache, and in this group, a trigger such as emotional stress and infection could also be identified in 9 (60%).

Unlike in cannabinoid hyperemesis syndrome, most patients with cyclic vomiting syndrome have a family history of migraine headache, and the prevalence of psychological stressors is high.³¹ Also, patients with cannabinoid hyperemesis syndrome do not respond to medications that usually abort migraine episodes,¹⁵ whereas patients with cyclic vomiting syndrome, especially those who have a family history of migraines, may respond to antimigraine medications such as triptans. There is evidence of clinical psychological overlap between cyclic vomiting syndrome, abdominal migraine, and migraine headaches. Some authors recommend antimigraine therapy even in the absence of a family or personal history of migraine if, after a careful history and physical examination, the diagnosis of cyclic vomiting syndrome seems likely. Moreover, nonmedical management such as sleep, dark rooms, and quiet environment are not as effective in cannabinoid hyperemesis syndrome as they are in cyclic vomiting syndrome.¹⁸

Psychogenic vomiting

Psychogenic vomiting is classically defined as vomiting caused by psychological mechanisms without any obvious organic cause.¹³ It occurs most commonly in patients with major depressive disorder or conversion disorder.³⁴ The mechanism appears to be a combination of past organic or gastrointestinal functional abnormalities and emotional problems, and multiple patterns of vomiting can occur. Most of these patients can be treated with behavioral therapy, antidepressant drug therapy, and supportive psychotherapy.^34,35

ASKING A SERIES OF QUESTIONS

Most patients with cannabinoid hyperemesis syndrome have a history of frequent visits to emergency departments or clinics for persistent nausea and vomiting, and they may have undergone extensive diagnostic workups to exclude structural, inflammatory, infectious, and functional diseases of the bowel.^23,24

To prevent unnecessary testing and use of healthcare resources, Wallace et al³² proposed an algorithm to help guide clinicians in diagnosing and treating patients with suspected cannabinoid hyperemesis syndrome. A patient presenting with severe nausea and vomiting should prompt a series of questions:

Do the signs and symptoms suggest a severe underlying medical cause? If so, this should be pursued.

Do symptoms improve while taking a hot shower or bath? If not, pursue an appropriate diagnostic evaluation and treatment for conditions other than cannabinoid hyperemesis syndrome.

Is the bathing compulsive? If not, consider other diagnoses, but remain suspicious about cannabinoid hyperemesis syndrome.

Does the patient currently use cannabis daily or almost daily, and has the patient done so for at least the past year? If the patient denies using cannabis, a urine drug screen for THC may be useful. If the patient admits to use, a presumptive diagnosis of cannabinoid hyperemesis syndrome can be made.

Does the patient have signs or symptoms of volume depletion, or is the patient unable to tolerate oral hydration? Encourage oral hydration or provide intravenous hydration, and provide cannabis cessation counseling.

Do the symptoms improve? If yes, great! Provide cessation counseling, resources, and follow-up. If not:

Is the patient still using cannabis? If not, it is time to rethink the diagnosis.

Treatment in the acute setting is supportive and includes intravenous hydration and correction of electrolytes. Conventional antiemetics such as ondansetron, metoclopramide, prochlorperazine, and promethazine have not been effective in relieving hyperemesis.^9,12,14 This implies that the mechanism of emesis likely does not involve dopaminergic and serotonin pathways in the central and autonomic nervous systems.

Cessation of cannabis use is key for long-term resolution of symptoms. Efforts should be made to provide counseling and encourage patients to stop using the drug entirely (Figure 1).

SOMETHING TO THINK ABOUT

With the high prevalence of chronic cannabis abuse and the recent legalization of recreational marijuana use, we will all likely encounter a patient with cannabinoid hyperemesis. With adequate knowledge of this phenomenon, we can avoid unnecessary workups and inappropriate medical and surgical treatment in patients presenting with recurrent vomiting of unknown cause. The diagnosis can easily be made by simply asking for a history of chronic marijuana use and symptoms related to cannabinoid hyperemesis syndrome, such as relief of symptoms with hot baths or showers and with marijuana cessation.

Conservative management and fluid resuscitation is important in the acute setting, but cessation of marijuana use and follow-up counseling are the key components for treating patients with cannabinoid hyperemesis syndrome and for preventing recurrence.

With the growing use of marijuana, reports have appeared of a newly recognized condition in long-term heavy users termed cannabinoid hyperemesis syndrome.¹

This syndrome is interesting for at least two reasons. First, paradoxically, marijuana appears to have an emetic effect with chronic use, whereas it usually has the opposite effect and is used as an antiemetic in patients undergoing chemotherapy. Second, patients develop a compulsion to bathe or shower in extremely hot water to relieve the symptoms.

In this article, we review the pathophysiology, clinical presentation, diagnosis, and management of this emerging condition.

MARIJUANA USE ON THE RISE

Marijuana is the most widely used illicit drug worldwide. Although statistics on its use vary, a report from the Pew Research Center² stated that 49% of Americans say they have tried it. Several states now allow the use of marijuana for medicinal purposes, and Colorado and Washington have legalized it for recreational use. This marks a major turning point and may accelerate the slow-growing acceptance of marijuana use in the United States.

Marijuana has been used to treat HIV-associated anorexia and wasting, convulsions, glaucoma, headache, and chemotherapy-induced nausea and vomiting.^3–5

Cannabinoid hyperemesis syndrome was first described in 2004 in South Australia.¹ Since its recognition, an increasing number of cases have been identified worldwide. However, there are still no population-based studies to estimate its exact prevalence.

THC PREVENTS VOMITING—AND CAUSES IT

Delta-9-tetrahydrocannabinol (THC) is the principal psychoactive component in marijuana.^6,7 There are two types of cannabinoid receptors in humans: CB1 and CB2. Both are found in the central nervous system and autonomic nervous system. Activation of CB1 receptors is responsible for the psychoactive effects of cannabinoids such as altered consciousness, euphoria, relaxation, perceptual disturbances, intensified sensory experiences, cognitive impairment, and increased reaction time. The physiologic role of CB2 is not known.

THC as an antiemetic

The antiemetic property of THC is not well understood but has been linked to activation of CB1 receptors found on the enteric plexus, presynaptic parasympathetic system, and central nervous system, particularly the cerebellum, hypothalamus, and vomiting center in the medulla.^1,8–12 Stimulation and blockade of CB1 receptors can inhibit and induce vomiting in a dose-dependent manner, implicating endogenous cannabinoids in emetic circuits.¹²

THC as a proemetic

The mechanism of the paradoxical hyperemetic effect of THC is unknown, but several concepts have been proposed.

Chronic cannabis use can lead to down-regulation of CB1 receptors.¹³ Simonetto et al¹⁰ suggested that the central effects of long-term cannabis use on the hypothalamic-pituitary-adrenal axis may play a central role in the development of hyperemesis.¹⁰

Cannabinoids have a long half-life and are lipophilic.¹ When used infrequently, they prevent vomiting. But with chronic use, high concentrations of THC can accumulate in the body, including cerebral fat, and can cause severe nausea and vomiting.^8,9 This paradoxic hyperemesis was observed in people using intravenous crude marijuana extract.⁷ The same response was also noted in ferrets injected with 2-arachidonoylglycerol, a potent cannabinoid agonist.¹¹

Patients who experience hyperemesis from chronic cannabis use may also have a genetic variation in their hepatic drug-transforming enzymes that results in excessive levels of cannabis metabolites that promote emesis.^1,14

Delayed gastric emptying has also been linked to the proemetic effect of THC. However, this association became controversial when a large case series study showed that only 30% of patients with cannabinoid hyperemesis syndrome had delayed emptying on gastric scintigraphy.¹⁰

It is also possible that excessive stimulation of cannabinoid receptors in the gut can cause diffuse splanchnic vasodilation and contribute to the abdominal pain.¹³

DIAGNOSING CANNABINOID HYPEREMESIS SYNDROME

Cannabinoid hyperemesis syndrome is a clinical diagnosis typically seen in young patients (under age 50) with a long history of marijuana use. They present with severe, cyclic nausea and vomiting and admit to compulsively taking extremely hot showers or baths. Most patients report using marijuana for more than a year before developing episodes of severe vomiting. However, one study found that as many as 32% of patients had used it less than 1 year before experiencing symptoms.¹⁰

Other associated nonspecific symptoms are diaphoresis, bloating, abdominal discomfort, flushing, and weight loss. Symptoms are relieved with long, hot showers or baths and cessation of marijuana use. Taking a complete history is key to making the diagnosis.

In 2004, Allen et al¹ first defined cannabinoid hyperemesis as excessive marijuana use associated with cyclical vomiting and abdominal pain.¹ In 2012, Simonetto et al¹⁰ proposed diagnostic criteria (Table 1). Although not yet validated, these criteria are based on the largest series of cases of cannabinoid hyperemesis syndrome to date (98 patients).¹⁰

THE THREE PHASES OF CANNABINOID HYPEREMESIS

The clinical presentation of cannabinoid hyperemesis syndrome can be divided into three phases: prodromal, vomiting, and resolution.

Prodromal phase

During this phase, patients often appear anxious and agitated and display a spectrum of autonomic symptoms such as sweating, flushing, and constantly sipping water due to thirst. They may sometimes have abdominal pain that is usually epigastric but may also be diffuse. Their symptoms are associated with severe nausea, usually early in the morning or when they see or smell food. Appetite and eating patterns remain normal. Compulsive hot bathing or showering is minimal at this phase.

Vomiting phase

In this next phase, patients experience incapacitating nausea and vomiting that may occur without warning and are resistant to conventional antiemetics such as ondansetron and promethazine.¹⁴ However, patients eventually learn that hot baths or showers relieve the symptoms, and this behavior eventually becomes a compulsion. The higher the temperature of the water, the better the effect on symptoms.¹ Low-grade pyrexia, excessive thirst, orthostasis, abdominal tenderness, weight loss, and sometimes even superficial skin burns have been reported.^1,9,15–18

Recovery phase

During the final phase of cannabinoid hyperemesis syndrome, most patients experience marked resolution of symptoms after 24 to 48 hours of conservative management (bowel rest until symptoms resolve, slowly advancing diet as tolerated, intravenous fluids, and electrolyte monitoring and repletion as necessary), and most importantly, cessation of cannabis use. However, the time from cessation of marijuana use to resolution of symptoms may be as long as 1 week to 1 month.^1,10,14 Patients begin to resume their normal diet and daily activities. The bathing-showering compulsion subsides, and patients regain lost weight after 3 to 6 months.¹

In all case series and reports, resumption of cannabis use causes the symptoms to recur. This recurrence is compelling evidence that cannabis is the cause of the hyperemesis and should be part of the essential criteria for the diagnosis of cannabinoid hyperemesis syndrome.

WHY COMPULSIVE HOT BATHING?

The mechanism behind this unique characteristic of cannabinoid hyperemesis syndrome is not known. Several theories have been suggested, but no study has identified the exact explanation for this phenomenon.^{1,9,10,13–15,17–31}

One suggested mechanism is a response by the thermoregulatory center of the brain to the dose-dependent hypothermic effects of THC, or even a direct effect of CB1 receptor activation in the hypothalamus.⁹ Cannabis toxicity could disrupt the equilibrium of satiety, thirst, digestive, and thermoregulatory systems of the hypothalamus, and this interference could resolve with hot bathing.¹

The so-called “cutaneous steal” syndrome has also been proposed, in which cutaneous vasodilation caused by hot water decreases the blood volume available for the splanchnic circulation thought to be responsible for the abdominal pain and vomiting.¹³ The compulsive hot bathing may also be a response by the brain to the anxiety or psychological stress induced by severe nausea and vomiting.¹⁴

DIFFERENTIAL DIAGNOSIS

The differential diagnosis of cannabinoid hyperemesis syndrome includes mainly cyclic vomiting syndrome and psychogenic vomiting. A careful history is useful, as is ruling out medication-induced reactions, toxins, pregnancy, and gastrointestinal, neurologic, metabolic, and endocrine causes. All three of these vomiting syndromes can present with a cyclic pattern of nausea and vomiting. Cannabis use is common in all three and so is not helpful in differentiating them. But the characteristic compulsive hot bathing and showering is unique and pathognomonic of cannabinoid hyperemesis syndrome.³²

Endoscopic examination may reveal esophagitis and gastritis from severe bouts of retching.²⁶

Cyclic vomiting syndrome

The Rome III criteria for the diagnosis of cyclic vomiting syndrome include three or more stereotypic episodes of acute-onset nausea and vomiting lasting less than 1 week, alternating with intervals of completely normal health. The criteria should be fulfilled for the previous 3 months with symptom onset at least 6 months before diagnosis.³³

In a series of 17 patients with adult-onset cyclic vomiting syndrome,¹⁸ the average age at onset was 30, and 13 (76%) of the patients were women. Fifteen (88%) of the patients experienced a prodrome or aura of abdominal pain or headache, and in this group, a trigger such as emotional stress and infection could also be identified in 9 (60%).

Unlike in cannabinoid hyperemesis syndrome, most patients with cyclic vomiting syndrome have a family history of migraine headache, and the prevalence of psychological stressors is high.³¹ Also, patients with cannabinoid hyperemesis syndrome do not respond to medications that usually abort migraine episodes,¹⁵ whereas patients with cyclic vomiting syndrome, especially those who have a family history of migraines, may respond to antimigraine medications such as triptans. There is evidence of clinical psychological overlap between cyclic vomiting syndrome, abdominal migraine, and migraine headaches. Some authors recommend antimigraine therapy even in the absence of a family or personal history of migraine if, after a careful history and physical examination, the diagnosis of cyclic vomiting syndrome seems likely. Moreover, nonmedical management such as sleep, dark rooms, and quiet environment are not as effective in cannabinoid hyperemesis syndrome as they are in cyclic vomiting syndrome.¹⁸

Psychogenic vomiting

Psychogenic vomiting is classically defined as vomiting caused by psychological mechanisms without any obvious organic cause.¹³ It occurs most commonly in patients with major depressive disorder or conversion disorder.³⁴ The mechanism appears to be a combination of past organic or gastrointestinal functional abnormalities and emotional problems, and multiple patterns of vomiting can occur. Most of these patients can be treated with behavioral therapy, antidepressant drug therapy, and supportive psychotherapy.^34,35

ASKING A SERIES OF QUESTIONS

Most patients with cannabinoid hyperemesis syndrome have a history of frequent visits to emergency departments or clinics for persistent nausea and vomiting, and they may have undergone extensive diagnostic workups to exclude structural, inflammatory, infectious, and functional diseases of the bowel.^23,24

To prevent unnecessary testing and use of healthcare resources, Wallace et al³² proposed an algorithm to help guide clinicians in diagnosing and treating patients with suspected cannabinoid hyperemesis syndrome. A patient presenting with severe nausea and vomiting should prompt a series of questions:

Do the signs and symptoms suggest a severe underlying medical cause? If so, this should be pursued.

Do symptoms improve while taking a hot shower or bath? If not, pursue an appropriate diagnostic evaluation and treatment for conditions other than cannabinoid hyperemesis syndrome.

Is the bathing compulsive? If not, consider other diagnoses, but remain suspicious about cannabinoid hyperemesis syndrome.

Does the patient currently use cannabis daily or almost daily, and has the patient done so for at least the past year? If the patient denies using cannabis, a urine drug screen for THC may be useful. If the patient admits to use, a presumptive diagnosis of cannabinoid hyperemesis syndrome can be made.

Does the patient have signs or symptoms of volume depletion, or is the patient unable to tolerate oral hydration? Encourage oral hydration or provide intravenous hydration, and provide cannabis cessation counseling.

Do the symptoms improve? If yes, great! Provide cessation counseling, resources, and follow-up. If not:

Is the patient still using cannabis? If not, it is time to rethink the diagnosis.

Treatment in the acute setting is supportive and includes intravenous hydration and correction of electrolytes. Conventional antiemetics such as ondansetron, metoclopramide, prochlorperazine, and promethazine have not been effective in relieving hyperemesis.^9,12,14 This implies that the mechanism of emesis likely does not involve dopaminergic and serotonin pathways in the central and autonomic nervous systems.

Cessation of cannabis use is key for long-term resolution of symptoms. Efforts should be made to provide counseling and encourage patients to stop using the drug entirely (Figure 1).

SOMETHING TO THINK ABOUT

With the high prevalence of chronic cannabis abuse and the recent legalization of recreational marijuana use, we will all likely encounter a patient with cannabinoid hyperemesis. With adequate knowledge of this phenomenon, we can avoid unnecessary workups and inappropriate medical and surgical treatment in patients presenting with recurrent vomiting of unknown cause. The diagnosis can easily be made by simply asking for a history of chronic marijuana use and symptoms related to cannabinoid hyperemesis syndrome, such as relief of symptoms with hot baths or showers and with marijuana cessation.

Conservative management and fluid resuscitation is important in the acute setting, but cessation of marijuana use and follow-up counseling are the key components for treating patients with cannabinoid hyperemesis syndrome and for preventing recurrence.

Bell palsy is an idiopathic peripheral nerve disorder involving the facial nerve (ie, cranial nerve VII) and manifesting as acute, ipsilateral facial muscle weakness. It is named after Sir Charles Bell, who in 1821 first described the anatomy of the facial nerve.¹ Although the disorder is clinically benign, patients can be devastated by its disfigurement.

The annual incidence of Bell palsy is 20 per 100,000, with no predilection for sex or ethnicity. It can affect people at any age, but the incidence is slightly higher after age 40.^2,3 Risk factors include diabetes, pregnancy, severe preeclampsia, obesity, and hypertension.^4–7

THE FACIAL NERVE IS VULNERABLE TO TRAUMA AND COMPRESSION

A basic understanding of the neuroanatomy of the facial nerve provides clues for distinguishing a central lesion from a peripheral lesion. This differentiation is important because the causes and management differ.

The facial nerve is a mixed sensory and motor nerve, carrying fibers involved in facial expression, taste, lacrimation, salivation, and sensation of the ear. It originates in the lower pons and exits the brainstem ventrally at the pontomedullary junction. After entering the internal acoustic meatus, it travels 20 to 30 mm in the facial canal, the longest bony course of any cranial nerve, making it highly susceptible to trauma and compression by edema.⁸

In the facial canal, it makes a posterior and inferior turn, forming a bend (ie, the genu of the facial nerve). The genu is proximal to the geniculate ganglion, which contains the facial nerve’s primary sensory neurons for taste and sensation. The motor branch of the facial nerve then exits the cranium via the stylomastoid foramen and passes through the parotid gland, where it divides into temporofacial and cervicofacial trunks.⁹

The facial nerve has five terminal branches that innervate the muscles of facial expression:

• The temporal branch (muscles of the forehead and superior part of the orbicularis oculi)
• The zygomatic branch (muscles of the nasolabial fold and cheek, eg, nasalis and zygomaticus).
• The buccal branch (the buccinators and inferior part of the orbicularis oculi)
• The marginal mandibular branch (the depressors of the mouth, eg, depressor anguli and mentalis)
• The cervical branch (the platysma muscle).

INFLAMMATION IS BELIEVED TO BE RESPONSIBLE

Although the precise cause of Bell palsy is not known, one theory is that inflammation of the nerve causes focal edema, demyelination, and ischemia. Several studies have suggested that herpes virus simplex type 1 infection may be involved.¹⁰

FACIAL DROOPING, EYELID WEAKNESS, OTHER SYMPTOMS

Symptoms of Bell palsy include ipsilateral sagging of the eyebrow, drooping of the face, flattening of the nasolabial fold, and inability to fully close the eye, pucker the lips, or raise the corner of the mouth (Figure 1). Symptoms develop within hours and are maximal by 3 days.

About 70% of patients have associated ipsilateral pain around the ear. If facial pain is present with sensory and hearing loss, a tumor of the parotid gland or viral otitis must be considered.¹¹ Other complaints may include hyperacusis due to disruption of nerve fibers to the stapedius muscle, changes in taste, and dry eye from parasympathetic dysfunction. Some patients report paresthesias over the face, which most often represent motor symptoms misconstrued as sensory changes.

PHYSICAL EXAMINATION

The clinical examination should include a complete neurologic and general examination, including otoscopy and attention to the skin and parotid gland. Vesicles or scabbing around the ear should prompt testing for herpes zoster. Careful observation during the interview while the patient is talking may reveal subtle signs of weakness and provide additional clues.

A systematic approach to the assessment of a patient with suspected Bell palsy is recommended (Table 1) and outlined below:

Does the patient have peripheral facial palsy?

In Bell palsy, wrinkling of the forehead on the affected side when raising the eyebrows is either asymmetrical or absent.

If the forehead muscles are spared and the lower face is weak, this signifies a central lesion such as a stroke or other structural abnormality and not a peripheral lesion of the facial nerve (eg, Bell palsy).

Can the patient close the eyes tightly?

Normally, the patient should be able to close both eyes tightly, and the eyelashes should be buried between the eyelids. In Bell palsy, when the patient attempts to close the eyes, the affected side shows incomplete closure and the eye may remain partly open.

Assess the strength of the orbicularis oculi by trying to open the eyes. The patient who is attempting to close the eyelids tightly but cannot will demonstrate the Bell phenomenon, ie, the examiner is able to force open the eyelids, and the eyes are deviated upward and laterally.

Closely observe the blink pattern, as the involved side in Bell palsy may slightly lag behind the normal eye, and the patient may be unable to close the eye completely.

Is the smile symmetric?

Note flattening of the nasolabial fold on one side, which indicates facial weakness.

Can the patient puff out the cheeks?

Ask the patient to hold air in the mouth against resistance. This assesses the strength of the buccinator muscle.

Can the patient purse the lips?

Ask the patient to pucker or purse the lips and observe for asymmetry or weakness on the affected side.

Test the orbicularis oris muscle by trying to spread the lips apart while the patient resists, and observe for weakness on one side.

Is there a symmetric grimace?

This will test the muscles involved in depressing the angles of the mouth and platysma.

Are taste, sensation, and hearing intact?

Other testable functions of the facial nerve, including taste, sensation, and hearing, do not always need to be assessed but can be in patients with specific sensory deficits.

Facial palsy that does not improve after 3 weeks should prompt a referral to a neurologist

Abnormalities in taste can support localization of the problem either proximal or distal to the branch point of fibers mediating taste. The facial nerve supplies taste fibers to the anterior two-thirds of the tongue. Sweet and salty taste can be screened with sugar and salt. Tell the patient to close the eyes, and using a tongue blade, apply a small amount of sugar or salt on the side of the tongue. Ask the patient to identify the taste and repeat with the other sample after he or she has rinsed the mouth.

Somatic sensory fibers supplied by the facial nerve innervate the inner ear and a small area behind the ear, but these may be difficult to assess objectively. Formal audiologic testing may be needed if hearing is impaired.

Facial nerve reflexes

A number of facial reflexes can be tested, including the orbicularis oculi, palpebral-oculogyric, and corneal reflexes.¹²

The orbicularis oculi reflex is tested by gentle finger percussion of the glabella while observing for involuntary blinking with each stimulus. The afferent branch of this reflex is carried by the trigeminal nerve, while the efferent response is carried by the facial nerve. In peripheral facial nerve palsy, this reflex is weakened or absent on the affected side.

The palpebral-oculogyric reflex, or Bell phenomenon, produces upward and lateral deviation of the eyes when attempting forceful eyelid closure. In this reflex, the afferent fibers are carried by the facial nerve and the efferent fibers travel in the oculomotor nerve to the superior rectus muscle. In Bell palsy, this reflex is visible because of failure of adequate eyelid closure.

The corneal reflex is elicited by stimulating the cornea with a wisp of cotton, causing reflexive closure of the both eyes. The affected side may show slowed or absent lid closure when tested on either side. The sensory afferent fibers are carried by the trigeminal nerve, and the motor efferent fibers are carried by the facial nerve.

Grading of facial paralysis

The House-Brackmann scale is the most widely used tool for grading the degree of facial paralysis and for predicting recovery. Grades are I to VI, with grade I indicating normal function, and grade VI, complete paralysis.

Patients with some preserved motor function generally have good recovery, but those with complete paralysis may have long-term residual deficits.¹³

A DIAGNOSIS OF EXCLUSION

The diagnosis of Bell palsy is made by excluding other causes of unilateral facial paralysis, and 30% to 60% of cases of facial palsy are caused by an underlying disorder that mimics Bell palsy, including central nervous system lesion (eg, stroke, demyelinating disease), parotid gland tumor, Lyme disease, Ramsay Hunt syndrome, granulomatous disease, otitis media, cholesteatoma, diabetes, trauma, and Guillain-Barré syndrome (Table 2).^14,15 Many of these conditions have associated features that help distinguish them from Bell palsy. Facial palsy that does not improve after 3 weeks should prompt referral to a neurologist.

Brain lesions

It is uncommon to have isolated facial palsy with a cortical or subcortical brain lesion, since the corticobulbar and corticospinal tracts travel in close proximity. Cortical signs such as hemiparesis, hemisensory loss, neglect, and dysarthria suggest a lesion of the cerebral cortex. Additionally, forehead muscle sparing is expected in supranuclear lesions.

Brainstem lesions can manifest with multiple ipsilateral cranial nerve palsies and contralateral limb weakness. Sarcoidosis and leptomeningeal carcinomatosis tend to involve the skull base and present with multiple cranial neuropathies.

Tumors of the brain or parotid gland have an insidious onset and may cause systemic signs such as fevers, chills, and weight loss. Headache, seizures, and hearing loss indicate an intracranial lesion. A palpable mass near the ear, neck, or parotid gland requires imaging of the face to look for a parotid gland tumor.

Infection

A number of infections can cause acute facial paralysis. The most common is herpes simplex virus, and the next most common is varicella zoster.¹⁴ Herpes simplex virus, Ramsay Hunt syndrome, and Lyme disease may have associated pain and skin changes. Erythema of the tympanic membrane suggests otitis media, especially in the setting of ear pain and hearing loss.

Ramsay Hunt syndrome is caused by reactivation of the herpes zoster virus from the geniculate ganglion, affecting the facial nerve. Careful examination of the ear canal and the oropharynx may show vesicles.

In Lyme disease, facial palsy is the most common cranial neuropathy, seen in 50% to 63% of patients with Borrelia burgdorferi meningitis.^16,17 In people with a history of rash, arthralgia, tick bite, or travel to an endemic region, Lyme titers should be checked before starting the patient on corticosteroids.

Bilateral facial palsy is rare and occurs in fewer than 1% of patients. It has been reported in patients with Lyme disease, Guillain-Barré syndrome, sarcoidosis, diabetes mellitus, viral infection, and pontine glioma.¹⁸

DIAGNOSTIC EVALUATION

Serologic testing, electrodiagnostic studies, and imaging are not routinely necessary to diagnose Bell palsy

Serologic testing, electrodiagnostic studies, and imaging are not routinely necessary to diagnose Bell palsy. However, referral to the appropriate specialist (neurologist, otolaryngologist, optometrist, ophthalmologist) is advised if the patient has sparing of the forehead muscle, multiple cranial neuropathies, signs of infection, or persistent weakness without significant improvement at 3 weeks.

Laboratory testing

A complete blood cell count with differential may point to infection or a lymphoproliferative disorder. When indicated, screening for diabetes mellitus with fasting blood glucose or hemoglobin A_1c may be helpful. In Lyme-endemic regions, patients should undergo an enzyme-linked immunosorbent assay or an indirect fluorescent antibody test to screen for the disease. If positive, the diagnosis of Lyme disease should be confirmed by Western blot. If vesicles are present on examination, check serum antibodies for herpes zoster. In the appropriate clinical setting, angiotensin-converting enzyme, human immunodeficiency virus, and inflammatory markers can be tested.

Cerebrospinal fluid analysis is generally not helpful in diagnosing Bell palsy but can differentiate it from Guillain-Barré syndrome, leptomeningeal carcinomatosis, and infection involving the central nervous system.

Imaging

Imaging is not recommended in the initial evaluation of Bell palsy unless symptoms and the examination are atypical. From 5% to 7% of cases of facial palsy are caused by a tumor (eg, facial neuroma, cholesteatoma, hemangioma, meningioma), whether benign or malignant.^14,15 Therefore, in patients with insidious onset of symptoms that do not improve in about 3 weeks, contrast-enhanced computed tomography or gadolinium-enhanced magnetic resonance imaging of the internal auditory canal and face is warranted.

Electrodiagnostic studies

Electrodiagnostic testing is typically not part of the evaluation of acute Bell palsy, but in patients with complete paralysis, it may help assess the degree of nerve injury and the chances of recovery, especially since patients with complete paralysis have a higher risk of incomplete recovery.¹⁹ Electrodiagnostic studies should be performed at least 1 week after symptom onset to avoid false-negative results.

TREATMENT

The treatment of Bell palsy focuses on maximizing recovery and minimizing associated complications.

Protect the eyes

Patients who cannot completely close their eyes should be given instructions on ocular protective care to prevent exposure keratopathy. Frequent application of lubricant eyedrops with artificial tears during the day or ophthalmic ointment at bedtime is recommended. The physician should also recommend protective eyewear such as sunglasses during the day. Eye patching or taping at night may be useful but could be harmful if applied too loosely or too tightly. Patients with vision loss or eye irritation should be referred to an ophthalmologist.¹⁹

Corticosteroids are recommended in the first 72 hours

In two randomized clinical trials (conducted by Sullivan et al²⁰ in 511 patients and Engström et al²¹ in 829 patients), prednisolone was found to be beneficial if started within 72 hours of symptom onset.

In a double-blind, randomized, placebo-controlled study of prednisone in 58 patients, those who received the drug recovered faster, although long-term outcomes in these patients were not significantly different than those in the control group.²² The American Academy of Neurology²³ rated this study as class II, ie, not meeting all of its criteria for the highest level of evidence, class I. Nevertheless, although prednisone lacks class I evidence, its use is recommended because it is a precursor to its active metabolite, prednisolone, which has been studied extensively.

The current guidelines of the American Academy of Neurology, updated in 2012, state, “For patients with new-onset Bell palsy, steroids are highly likely to be effective and should be offered to increase the probability of recovery of facial nerve function”²³ (level A evidence, ie, established as effective). They also concluded that adverse effects of corticosteroids were generally minor and temporary.

Similarly, the guidelines of the American Academy of Otolaryngology–Head and Neck Surgery, published in 2013, recommend oral corticosteroids within 72 hours of onset of symptoms of Bell palsy for patients age 16 and older.¹⁹ The recommendation is for a 10-day course of corticosteroids with at least 5 days at a high dose (prednisolone 50 mg orally daily for 10 days, or prednisone 60 mg orally daily for 5 days, followed by a 5-day taper). The benefit of corticosteroids after 72 hours is unclear (Table 3).¹⁹

Even though the guidelines recommend corticosteroids, the decision to use them in diabetic patients and pregnant women should be individualized. Discretion is advised, as not all patients with Bell palsy need to be treated. Most recover spontaneously, especially those with mild symptoms.

Antiviral therapy may offer modest benefit

Antiviral therapy has not been shown to be beneficial in Bell palsy, and current guidelines do not recommend oral antiviral therapy alone.¹⁹ However, an antiviral combined with a corticosteroid may offer modest benefit if started within 72 hours of symptom onset (level C evidence, ie, possibly effective).²³ Patients starting antiviral therapy should understand that its benefit has not been established.

Surgical decompression remains controversial

A Cochrane systematic review in 2011 found insufficient evidence regarding the safety and efficacy of surgical intervention in Bell palsy.²⁴ Surgery should be considered only for patients with complete paralysis with a greater than 90% reduction in motor amplitude on a nerve conduction study compared with the unaffected side, and absent volitional activity on needle examination.^19,25

Acupuncture: No recommendation

Currently, there is no recommendation for acupuncture in the treatment of Bell palsy.¹⁹ A recent randomized clinical trial suggests benefit from acupuncture combined with corticosteroids,²⁶ but high-quality studies to support its use are lacking.²⁶

Physical therapy: Insufficient evidence

There is insufficient evidence to show that physical therapy has benefit—or harm—in Bell palsy. However, some low-quality studies indicated that facial exercises and mime therapy may improve function in patients with moderate paralysis.²⁷

Follow-up

Instruct patients to call at 2 weeks to report progress of symptoms

Patients should be instructed to call at 2 weeks to report progress of symptoms and to be reevaluated within or at 1 month, with close attention to facial weakness and eye irritation. Further evaluation is needed if there has been no improvement, if symptoms have worsened, or if new symptoms have appeared.

The psychosocial impact of Bell palsy cannot be discounted, as the disfigurement can have negative implications for self-esteem and social relationships. Appropriate referral to an ophthalmologist, neurologist, otolaryngologist, social worker, or a plastic surgeon may be necessary.

COMPLICATIONS AND PROGNOSIS

Most patients with Bell palsy recover completely, but up to 30% have residual symptoms at 6 months.^14,20 Furthermore, although Bell palsy usually has a monophasic course, 7% to 12% of patients have a recurrence.^3,15

Long-term complications can include residual facial weakness, facial synkinesis, facial contracture, and facial spasm.^14,28 Incomplete eye closure may benefit from surgery (tarsorrhaphy or gold-weight implantation) to prevent corneal ulceration. Facial synkinesis is due to aberrant nerve regeneration and occurs in 15% to 20% of patients after recovery from Bell palsy.²⁹ Patients may describe tearing while chewing (“crocodile tears”), involuntary movement of the corners of the mouth with blinking, or ipsilateral eye-closing when the jaw opens (“jaw-winking”). Facial contracture, facial synkinesis, and facial spasm can be treated with botulinum toxin injection.³⁰

Bell palsy is an idiopathic peripheral nerve disorder involving the facial nerve (ie, cranial nerve VII) and manifesting as acute, ipsilateral facial muscle weakness. It is named after Sir Charles Bell, who in 1821 first described the anatomy of the facial nerve.¹ Although the disorder is clinically benign, patients can be devastated by its disfigurement.

The annual incidence of Bell palsy is 20 per 100,000, with no predilection for sex or ethnicity. It can affect people at any age, but the incidence is slightly higher after age 40.^2,3 Risk factors include diabetes, pregnancy, severe preeclampsia, obesity, and hypertension.^4–7

THE FACIAL NERVE IS VULNERABLE TO TRAUMA AND COMPRESSION

A basic understanding of the neuroanatomy of the facial nerve provides clues for distinguishing a central lesion from a peripheral lesion. This differentiation is important because the causes and management differ.

The facial nerve is a mixed sensory and motor nerve, carrying fibers involved in facial expression, taste, lacrimation, salivation, and sensation of the ear. It originates in the lower pons and exits the brainstem ventrally at the pontomedullary junction. After entering the internal acoustic meatus, it travels 20 to 30 mm in the facial canal, the longest bony course of any cranial nerve, making it highly susceptible to trauma and compression by edema.⁸

In the facial canal, it makes a posterior and inferior turn, forming a bend (ie, the genu of the facial nerve). The genu is proximal to the geniculate ganglion, which contains the facial nerve’s primary sensory neurons for taste and sensation. The motor branch of the facial nerve then exits the cranium via the stylomastoid foramen and passes through the parotid gland, where it divides into temporofacial and cervicofacial trunks.⁹

The facial nerve has five terminal branches that innervate the muscles of facial expression:

• The temporal branch (muscles of the forehead and superior part of the orbicularis oculi)
• The zygomatic branch (muscles of the nasolabial fold and cheek, eg, nasalis and zygomaticus).
• The buccal branch (the buccinators and inferior part of the orbicularis oculi)
• The marginal mandibular branch (the depressors of the mouth, eg, depressor anguli and mentalis)
• The cervical branch (the platysma muscle).

INFLAMMATION IS BELIEVED TO BE RESPONSIBLE

Although the precise cause of Bell palsy is not known, one theory is that inflammation of the nerve causes focal edema, demyelination, and ischemia. Several studies have suggested that herpes virus simplex type 1 infection may be involved.¹⁰

FACIAL DROOPING, EYELID WEAKNESS, OTHER SYMPTOMS

Symptoms of Bell palsy include ipsilateral sagging of the eyebrow, drooping of the face, flattening of the nasolabial fold, and inability to fully close the eye, pucker the lips, or raise the corner of the mouth (Figure 1). Symptoms develop within hours and are maximal by 3 days.

About 70% of patients have associated ipsilateral pain around the ear. If facial pain is present with sensory and hearing loss, a tumor of the parotid gland or viral otitis must be considered.¹¹ Other complaints may include hyperacusis due to disruption of nerve fibers to the stapedius muscle, changes in taste, and dry eye from parasympathetic dysfunction. Some patients report paresthesias over the face, which most often represent motor symptoms misconstrued as sensory changes.

PHYSICAL EXAMINATION

The clinical examination should include a complete neurologic and general examination, including otoscopy and attention to the skin and parotid gland. Vesicles or scabbing around the ear should prompt testing for herpes zoster. Careful observation during the interview while the patient is talking may reveal subtle signs of weakness and provide additional clues.

A systematic approach to the assessment of a patient with suspected Bell palsy is recommended (Table 1) and outlined below:

Does the patient have peripheral facial palsy?

In Bell palsy, wrinkling of the forehead on the affected side when raising the eyebrows is either asymmetrical or absent.

If the forehead muscles are spared and the lower face is weak, this signifies a central lesion such as a stroke or other structural abnormality and not a peripheral lesion of the facial nerve (eg, Bell palsy).

Can the patient close the eyes tightly?

Normally, the patient should be able to close both eyes tightly, and the eyelashes should be buried between the eyelids. In Bell palsy, when the patient attempts to close the eyes, the affected side shows incomplete closure and the eye may remain partly open.

Assess the strength of the orbicularis oculi by trying to open the eyes. The patient who is attempting to close the eyelids tightly but cannot will demonstrate the Bell phenomenon, ie, the examiner is able to force open the eyelids, and the eyes are deviated upward and laterally.

Closely observe the blink pattern, as the involved side in Bell palsy may slightly lag behind the normal eye, and the patient may be unable to close the eye completely.

Is the smile symmetric?

Note flattening of the nasolabial fold on one side, which indicates facial weakness.

Can the patient puff out the cheeks?

Ask the patient to hold air in the mouth against resistance. This assesses the strength of the buccinator muscle.

Can the patient purse the lips?

Ask the patient to pucker or purse the lips and observe for asymmetry or weakness on the affected side.

Test the orbicularis oris muscle by trying to spread the lips apart while the patient resists, and observe for weakness on one side.

Is there a symmetric grimace?

This will test the muscles involved in depressing the angles of the mouth and platysma.

Are taste, sensation, and hearing intact?

Other testable functions of the facial nerve, including taste, sensation, and hearing, do not always need to be assessed but can be in patients with specific sensory deficits.

Facial palsy that does not improve after 3 weeks should prompt a referral to a neurologist

Abnormalities in taste can support localization of the problem either proximal or distal to the branch point of fibers mediating taste. The facial nerve supplies taste fibers to the anterior two-thirds of the tongue. Sweet and salty taste can be screened with sugar and salt. Tell the patient to close the eyes, and using a tongue blade, apply a small amount of sugar or salt on the side of the tongue. Ask the patient to identify the taste and repeat with the other sample after he or she has rinsed the mouth.

Somatic sensory fibers supplied by the facial nerve innervate the inner ear and a small area behind the ear, but these may be difficult to assess objectively. Formal audiologic testing may be needed if hearing is impaired.

Facial nerve reflexes

A number of facial reflexes can be tested, including the orbicularis oculi, palpebral-oculogyric, and corneal reflexes.¹²

The orbicularis oculi reflex is tested by gentle finger percussion of the glabella while observing for involuntary blinking with each stimulus. The afferent branch of this reflex is carried by the trigeminal nerve, while the efferent response is carried by the facial nerve. In peripheral facial nerve palsy, this reflex is weakened or absent on the affected side.

The palpebral-oculogyric reflex, or Bell phenomenon, produces upward and lateral deviation of the eyes when attempting forceful eyelid closure. In this reflex, the afferent fibers are carried by the facial nerve and the efferent fibers travel in the oculomotor nerve to the superior rectus muscle. In Bell palsy, this reflex is visible because of failure of adequate eyelid closure.

The corneal reflex is elicited by stimulating the cornea with a wisp of cotton, causing reflexive closure of the both eyes. The affected side may show slowed or absent lid closure when tested on either side. The sensory afferent fibers are carried by the trigeminal nerve, and the motor efferent fibers are carried by the facial nerve.

Grading of facial paralysis

The House-Brackmann scale is the most widely used tool for grading the degree of facial paralysis and for predicting recovery. Grades are I to VI, with grade I indicating normal function, and grade VI, complete paralysis.

Patients with some preserved motor function generally have good recovery, but those with complete paralysis may have long-term residual deficits.¹³

A DIAGNOSIS OF EXCLUSION

The diagnosis of Bell palsy is made by excluding other causes of unilateral facial paralysis, and 30% to 60% of cases of facial palsy are caused by an underlying disorder that mimics Bell palsy, including central nervous system lesion (eg, stroke, demyelinating disease), parotid gland tumor, Lyme disease, Ramsay Hunt syndrome, granulomatous disease, otitis media, cholesteatoma, diabetes, trauma, and Guillain-Barré syndrome (Table 2).^14,15 Many of these conditions have associated features that help distinguish them from Bell palsy. Facial palsy that does not improve after 3 weeks should prompt referral to a neurologist.

Brain lesions

It is uncommon to have isolated facial palsy with a cortical or subcortical brain lesion, since the corticobulbar and corticospinal tracts travel in close proximity. Cortical signs such as hemiparesis, hemisensory loss, neglect, and dysarthria suggest a lesion of the cerebral cortex. Additionally, forehead muscle sparing is expected in supranuclear lesions.

Brainstem lesions can manifest with multiple ipsilateral cranial nerve palsies and contralateral limb weakness. Sarcoidosis and leptomeningeal carcinomatosis tend to involve the skull base and present with multiple cranial neuropathies.

Tumors of the brain or parotid gland have an insidious onset and may cause systemic signs such as fevers, chills, and weight loss. Headache, seizures, and hearing loss indicate an intracranial lesion. A palpable mass near the ear, neck, or parotid gland requires imaging of the face to look for a parotid gland tumor.

Infection

A number of infections can cause acute facial paralysis. The most common is herpes simplex virus, and the next most common is varicella zoster.¹⁴ Herpes simplex virus, Ramsay Hunt syndrome, and Lyme disease may have associated pain and skin changes. Erythema of the tympanic membrane suggests otitis media, especially in the setting of ear pain and hearing loss.

Ramsay Hunt syndrome is caused by reactivation of the herpes zoster virus from the geniculate ganglion, affecting the facial nerve. Careful examination of the ear canal and the oropharynx may show vesicles.

In Lyme disease, facial palsy is the most common cranial neuropathy, seen in 50% to 63% of patients with Borrelia burgdorferi meningitis.^16,17 In people with a history of rash, arthralgia, tick bite, or travel to an endemic region, Lyme titers should be checked before starting the patient on corticosteroids.

Bilateral facial palsy is rare and occurs in fewer than 1% of patients. It has been reported in patients with Lyme disease, Guillain-Barré syndrome, sarcoidosis, diabetes mellitus, viral infection, and pontine glioma.¹⁸

DIAGNOSTIC EVALUATION

Serologic testing, electrodiagnostic studies, and imaging are not routinely necessary to diagnose Bell palsy

Serologic testing, electrodiagnostic studies, and imaging are not routinely necessary to diagnose Bell palsy. However, referral to the appropriate specialist (neurologist, otolaryngologist, optometrist, ophthalmologist) is advised if the patient has sparing of the forehead muscle, multiple cranial neuropathies, signs of infection, or persistent weakness without significant improvement at 3 weeks.

Laboratory testing

A complete blood cell count with differential may point to infection or a lymphoproliferative disorder. When indicated, screening for diabetes mellitus with fasting blood glucose or hemoglobin A_1c may be helpful. In Lyme-endemic regions, patients should undergo an enzyme-linked immunosorbent assay or an indirect fluorescent antibody test to screen for the disease. If positive, the diagnosis of Lyme disease should be confirmed by Western blot. If vesicles are present on examination, check serum antibodies for herpes zoster. In the appropriate clinical setting, angiotensin-converting enzyme, human immunodeficiency virus, and inflammatory markers can be tested.

Cerebrospinal fluid analysis is generally not helpful in diagnosing Bell palsy but can differentiate it from Guillain-Barré syndrome, leptomeningeal carcinomatosis, and infection involving the central nervous system.

Imaging

Imaging is not recommended in the initial evaluation of Bell palsy unless symptoms and the examination are atypical. From 5% to 7% of cases of facial palsy are caused by a tumor (eg, facial neuroma, cholesteatoma, hemangioma, meningioma), whether benign or malignant.^14,15 Therefore, in patients with insidious onset of symptoms that do not improve in about 3 weeks, contrast-enhanced computed tomography or gadolinium-enhanced magnetic resonance imaging of the internal auditory canal and face is warranted.

Electrodiagnostic studies

Electrodiagnostic testing is typically not part of the evaluation of acute Bell palsy, but in patients with complete paralysis, it may help assess the degree of nerve injury and the chances of recovery, especially since patients with complete paralysis have a higher risk of incomplete recovery.¹⁹ Electrodiagnostic studies should be performed at least 1 week after symptom onset to avoid false-negative results.

TREATMENT

The treatment of Bell palsy focuses on maximizing recovery and minimizing associated complications.

Protect the eyes

Patients who cannot completely close their eyes should be given instructions on ocular protective care to prevent exposure keratopathy. Frequent application of lubricant eyedrops with artificial tears during the day or ophthalmic ointment at bedtime is recommended. The physician should also recommend protective eyewear such as sunglasses during the day. Eye patching or taping at night may be useful but could be harmful if applied too loosely or too tightly. Patients with vision loss or eye irritation should be referred to an ophthalmologist.¹⁹

Corticosteroids are recommended in the first 72 hours

In two randomized clinical trials (conducted by Sullivan et al²⁰ in 511 patients and Engström et al²¹ in 829 patients), prednisolone was found to be beneficial if started within 72 hours of symptom onset.

In a double-blind, randomized, placebo-controlled study of prednisone in 58 patients, those who received the drug recovered faster, although long-term outcomes in these patients were not significantly different than those in the control group.²² The American Academy of Neurology²³ rated this study as class II, ie, not meeting all of its criteria for the highest level of evidence, class I. Nevertheless, although prednisone lacks class I evidence, its use is recommended because it is a precursor to its active metabolite, prednisolone, which has been studied extensively.

The current guidelines of the American Academy of Neurology, updated in 2012, state, “For patients with new-onset Bell palsy, steroids are highly likely to be effective and should be offered to increase the probability of recovery of facial nerve function”²³ (level A evidence, ie, established as effective). They also concluded that adverse effects of corticosteroids were generally minor and temporary.

Similarly, the guidelines of the American Academy of Otolaryngology–Head and Neck Surgery, published in 2013, recommend oral corticosteroids within 72 hours of onset of symptoms of Bell palsy for patients age 16 and older.¹⁹ The recommendation is for a 10-day course of corticosteroids with at least 5 days at a high dose (prednisolone 50 mg orally daily for 10 days, or prednisone 60 mg orally daily for 5 days, followed by a 5-day taper). The benefit of corticosteroids after 72 hours is unclear (Table 3).¹⁹

Even though the guidelines recommend corticosteroids, the decision to use them in diabetic patients and pregnant women should be individualized. Discretion is advised, as not all patients with Bell palsy need to be treated. Most recover spontaneously, especially those with mild symptoms.

Antiviral therapy may offer modest benefit

Antiviral therapy has not been shown to be beneficial in Bell palsy, and current guidelines do not recommend oral antiviral therapy alone.¹⁹ However, an antiviral combined with a corticosteroid may offer modest benefit if started within 72 hours of symptom onset (level C evidence, ie, possibly effective).²³ Patients starting antiviral therapy should understand that its benefit has not been established.

Surgical decompression remains controversial

A Cochrane systematic review in 2011 found insufficient evidence regarding the safety and efficacy of surgical intervention in Bell palsy.²⁴ Surgery should be considered only for patients with complete paralysis with a greater than 90% reduction in motor amplitude on a nerve conduction study compared with the unaffected side, and absent volitional activity on needle examination.^19,25

Acupuncture: No recommendation

Currently, there is no recommendation for acupuncture in the treatment of Bell palsy.¹⁹ A recent randomized clinical trial suggests benefit from acupuncture combined with corticosteroids,²⁶ but high-quality studies to support its use are lacking.²⁶

Physical therapy: Insufficient evidence

There is insufficient evidence to show that physical therapy has benefit—or harm—in Bell palsy. However, some low-quality studies indicated that facial exercises and mime therapy may improve function in patients with moderate paralysis.²⁷

Follow-up

Instruct patients to call at 2 weeks to report progress of symptoms

Patients should be instructed to call at 2 weeks to report progress of symptoms and to be reevaluated within or at 1 month, with close attention to facial weakness and eye irritation. Further evaluation is needed if there has been no improvement, if symptoms have worsened, or if new symptoms have appeared.

The psychosocial impact of Bell palsy cannot be discounted, as the disfigurement can have negative implications for self-esteem and social relationships. Appropriate referral to an ophthalmologist, neurologist, otolaryngologist, social worker, or a plastic surgeon may be necessary.

COMPLICATIONS AND PROGNOSIS

Most patients with Bell palsy recover completely, but up to 30% have residual symptoms at 6 months.^14,20 Furthermore, although Bell palsy usually has a monophasic course, 7% to 12% of patients have a recurrence.^3,15

Long-term complications can include residual facial weakness, facial synkinesis, facial contracture, and facial spasm.^14,28 Incomplete eye closure may benefit from surgery (tarsorrhaphy or gold-weight implantation) to prevent corneal ulceration. Facial synkinesis is due to aberrant nerve regeneration and occurs in 15% to 20% of patients after recovery from Bell palsy.²⁹ Patients may describe tearing while chewing (“crocodile tears”), involuntary movement of the corners of the mouth with blinking, or ipsilateral eye-closing when the jaw opens (“jaw-winking”). Facial contracture, facial synkinesis, and facial spasm can be treated with botulinum toxin injection.³⁰

Bell palsy is an idiopathic peripheral nerve disorder involving the facial nerve (ie, cranial nerve VII) and manifesting as acute, ipsilateral facial muscle weakness. It is named after Sir Charles Bell, who in 1821 first described the anatomy of the facial nerve.¹ Although the disorder is clinically benign, patients can be devastated by its disfigurement.

The annual incidence of Bell palsy is 20 per 100,000, with no predilection for sex or ethnicity. It can affect people at any age, but the incidence is slightly higher after age 40.^2,3 Risk factors include diabetes, pregnancy, severe preeclampsia, obesity, and hypertension.^4–7

THE FACIAL NERVE IS VULNERABLE TO TRAUMA AND COMPRESSION

A basic understanding of the neuroanatomy of the facial nerve provides clues for distinguishing a central lesion from a peripheral lesion. This differentiation is important because the causes and management differ.

The facial nerve is a mixed sensory and motor nerve, carrying fibers involved in facial expression, taste, lacrimation, salivation, and sensation of the ear. It originates in the lower pons and exits the brainstem ventrally at the pontomedullary junction. After entering the internal acoustic meatus, it travels 20 to 30 mm in the facial canal, the longest bony course of any cranial nerve, making it highly susceptible to trauma and compression by edema.⁸

In the facial canal, it makes a posterior and inferior turn, forming a bend (ie, the genu of the facial nerve). The genu is proximal to the geniculate ganglion, which contains the facial nerve’s primary sensory neurons for taste and sensation. The motor branch of the facial nerve then exits the cranium via the stylomastoid foramen and passes through the parotid gland, where it divides into temporofacial and cervicofacial trunks.⁹

The facial nerve has five terminal branches that innervate the muscles of facial expression:

• The temporal branch (muscles of the forehead and superior part of the orbicularis oculi)
• The zygomatic branch (muscles of the nasolabial fold and cheek, eg, nasalis and zygomaticus).
• The buccal branch (the buccinators and inferior part of the orbicularis oculi)
• The marginal mandibular branch (the depressors of the mouth, eg, depressor anguli and mentalis)
• The cervical branch (the platysma muscle).

INFLAMMATION IS BELIEVED TO BE RESPONSIBLE

Although the precise cause of Bell palsy is not known, one theory is that inflammation of the nerve causes focal edema, demyelination, and ischemia. Several studies have suggested that herpes virus simplex type 1 infection may be involved.¹⁰

FACIAL DROOPING, EYELID WEAKNESS, OTHER SYMPTOMS

Symptoms of Bell palsy include ipsilateral sagging of the eyebrow, drooping of the face, flattening of the nasolabial fold, and inability to fully close the eye, pucker the lips, or raise the corner of the mouth (Figure 1). Symptoms develop within hours and are maximal by 3 days.

About 70% of patients have associated ipsilateral pain around the ear. If facial pain is present with sensory and hearing loss, a tumor of the parotid gland or viral otitis must be considered.¹¹ Other complaints may include hyperacusis due to disruption of nerve fibers to the stapedius muscle, changes in taste, and dry eye from parasympathetic dysfunction. Some patients report paresthesias over the face, which most often represent motor symptoms misconstrued as sensory changes.

PHYSICAL EXAMINATION

The clinical examination should include a complete neurologic and general examination, including otoscopy and attention to the skin and parotid gland. Vesicles or scabbing around the ear should prompt testing for herpes zoster. Careful observation during the interview while the patient is talking may reveal subtle signs of weakness and provide additional clues.

A systematic approach to the assessment of a patient with suspected Bell palsy is recommended (Table 1) and outlined below:

Does the patient have peripheral facial palsy?

In Bell palsy, wrinkling of the forehead on the affected side when raising the eyebrows is either asymmetrical or absent.

If the forehead muscles are spared and the lower face is weak, this signifies a central lesion such as a stroke or other structural abnormality and not a peripheral lesion of the facial nerve (eg, Bell palsy).

Can the patient close the eyes tightly?

Normally, the patient should be able to close both eyes tightly, and the eyelashes should be buried between the eyelids. In Bell palsy, when the patient attempts to close the eyes, the affected side shows incomplete closure and the eye may remain partly open.

Assess the strength of the orbicularis oculi by trying to open the eyes. The patient who is attempting to close the eyelids tightly but cannot will demonstrate the Bell phenomenon, ie, the examiner is able to force open the eyelids, and the eyes are deviated upward and laterally.

Closely observe the blink pattern, as the involved side in Bell palsy may slightly lag behind the normal eye, and the patient may be unable to close the eye completely.

Is the smile symmetric?

Note flattening of the nasolabial fold on one side, which indicates facial weakness.

Can the patient puff out the cheeks?

Ask the patient to hold air in the mouth against resistance. This assesses the strength of the buccinator muscle.

Can the patient purse the lips?

Ask the patient to pucker or purse the lips and observe for asymmetry or weakness on the affected side.

Test the orbicularis oris muscle by trying to spread the lips apart while the patient resists, and observe for weakness on one side.

Is there a symmetric grimace?

This will test the muscles involved in depressing the angles of the mouth and platysma.

Are taste, sensation, and hearing intact?

Other testable functions of the facial nerve, including taste, sensation, and hearing, do not always need to be assessed but can be in patients with specific sensory deficits.

Facial palsy that does not improve after 3 weeks should prompt a referral to a neurologist

Abnormalities in taste can support localization of the problem either proximal or distal to the branch point of fibers mediating taste. The facial nerve supplies taste fibers to the anterior two-thirds of the tongue. Sweet and salty taste can be screened with sugar and salt. Tell the patient to close the eyes, and using a tongue blade, apply a small amount of sugar or salt on the side of the tongue. Ask the patient to identify the taste and repeat with the other sample after he or she has rinsed the mouth.

Somatic sensory fibers supplied by the facial nerve innervate the inner ear and a small area behind the ear, but these may be difficult to assess objectively. Formal audiologic testing may be needed if hearing is impaired.

Facial nerve reflexes

A number of facial reflexes can be tested, including the orbicularis oculi, palpebral-oculogyric, and corneal reflexes.¹²

The orbicularis oculi reflex is tested by gentle finger percussion of the glabella while observing for involuntary blinking with each stimulus. The afferent branch of this reflex is carried by the trigeminal nerve, while the efferent response is carried by the facial nerve. In peripheral facial nerve palsy, this reflex is weakened or absent on the affected side.

The palpebral-oculogyric reflex, or Bell phenomenon, produces upward and lateral deviation of the eyes when attempting forceful eyelid closure. In this reflex, the afferent fibers are carried by the facial nerve and the efferent fibers travel in the oculomotor nerve to the superior rectus muscle. In Bell palsy, this reflex is visible because of failure of adequate eyelid closure.

The corneal reflex is elicited by stimulating the cornea with a wisp of cotton, causing reflexive closure of the both eyes. The affected side may show slowed or absent lid closure when tested on either side. The sensory afferent fibers are carried by the trigeminal nerve, and the motor efferent fibers are carried by the facial nerve.

Grading of facial paralysis

The House-Brackmann scale is the most widely used tool for grading the degree of facial paralysis and for predicting recovery. Grades are I to VI, with grade I indicating normal function, and grade VI, complete paralysis.

Patients with some preserved motor function generally have good recovery, but those with complete paralysis may have long-term residual deficits.¹³

A DIAGNOSIS OF EXCLUSION

The diagnosis of Bell palsy is made by excluding other causes of unilateral facial paralysis, and 30% to 60% of cases of facial palsy are caused by an underlying disorder that mimics Bell palsy, including central nervous system lesion (eg, stroke, demyelinating disease), parotid gland tumor, Lyme disease, Ramsay Hunt syndrome, granulomatous disease, otitis media, cholesteatoma, diabetes, trauma, and Guillain-Barré syndrome (Table 2).^14,15 Many of these conditions have associated features that help distinguish them from Bell palsy. Facial palsy that does not improve after 3 weeks should prompt referral to a neurologist.

Brain lesions

It is uncommon to have isolated facial palsy with a cortical or subcortical brain lesion, since the corticobulbar and corticospinal tracts travel in close proximity. Cortical signs such as hemiparesis, hemisensory loss, neglect, and dysarthria suggest a lesion of the cerebral cortex. Additionally, forehead muscle sparing is expected in supranuclear lesions.

Brainstem lesions can manifest with multiple ipsilateral cranial nerve palsies and contralateral limb weakness. Sarcoidosis and leptomeningeal carcinomatosis tend to involve the skull base and present with multiple cranial neuropathies.

Tumors of the brain or parotid gland have an insidious onset and may cause systemic signs such as fevers, chills, and weight loss. Headache, seizures, and hearing loss indicate an intracranial lesion. A palpable mass near the ear, neck, or parotid gland requires imaging of the face to look for a parotid gland tumor.

Infection

A number of infections can cause acute facial paralysis. The most common is herpes simplex virus, and the next most common is varicella zoster.¹⁴ Herpes simplex virus, Ramsay Hunt syndrome, and Lyme disease may have associated pain and skin changes. Erythema of the tympanic membrane suggests otitis media, especially in the setting of ear pain and hearing loss.

Ramsay Hunt syndrome is caused by reactivation of the herpes zoster virus from the geniculate ganglion, affecting the facial nerve. Careful examination of the ear canal and the oropharynx may show vesicles.

In Lyme disease, facial palsy is the most common cranial neuropathy, seen in 50% to 63% of patients with Borrelia burgdorferi meningitis.^16,17 In people with a history of rash, arthralgia, tick bite, or travel to an endemic region, Lyme titers should be checked before starting the patient on corticosteroids.

Bilateral facial palsy is rare and occurs in fewer than 1% of patients. It has been reported in patients with Lyme disease, Guillain-Barré syndrome, sarcoidosis, diabetes mellitus, viral infection, and pontine glioma.¹⁸

DIAGNOSTIC EVALUATION

Serologic testing, electrodiagnostic studies, and imaging are not routinely necessary to diagnose Bell palsy

Serologic testing, electrodiagnostic studies, and imaging are not routinely necessary to diagnose Bell palsy. However, referral to the appropriate specialist (neurologist, otolaryngologist, optometrist, ophthalmologist) is advised if the patient has sparing of the forehead muscle, multiple cranial neuropathies, signs of infection, or persistent weakness without significant improvement at 3 weeks.

Laboratory testing

A complete blood cell count with differential may point to infection or a lymphoproliferative disorder. When indicated, screening for diabetes mellitus with fasting blood glucose or hemoglobin A_1c may be helpful. In Lyme-endemic regions, patients should undergo an enzyme-linked immunosorbent assay or an indirect fluorescent antibody test to screen for the disease. If positive, the diagnosis of Lyme disease should be confirmed by Western blot. If vesicles are present on examination, check serum antibodies for herpes zoster. In the appropriate clinical setting, angiotensin-converting enzyme, human immunodeficiency virus, and inflammatory markers can be tested.

Cerebrospinal fluid analysis is generally not helpful in diagnosing Bell palsy but can differentiate it from Guillain-Barré syndrome, leptomeningeal carcinomatosis, and infection involving the central nervous system.

Imaging

Imaging is not recommended in the initial evaluation of Bell palsy unless symptoms and the examination are atypical. From 5% to 7% of cases of facial palsy are caused by a tumor (eg, facial neuroma, cholesteatoma, hemangioma, meningioma), whether benign or malignant.^14,15 Therefore, in patients with insidious onset of symptoms that do not improve in about 3 weeks, contrast-enhanced computed tomography or gadolinium-enhanced magnetic resonance imaging of the internal auditory canal and face is warranted.

Electrodiagnostic studies

Electrodiagnostic testing is typically not part of the evaluation of acute Bell palsy, but in patients with complete paralysis, it may help assess the degree of nerve injury and the chances of recovery, especially since patients with complete paralysis have a higher risk of incomplete recovery.¹⁹ Electrodiagnostic studies should be performed at least 1 week after symptom onset to avoid false-negative results.

TREATMENT

The treatment of Bell palsy focuses on maximizing recovery and minimizing associated complications.

Protect the eyes

Patients who cannot completely close their eyes should be given instructions on ocular protective care to prevent exposure keratopathy. Frequent application of lubricant eyedrops with artificial tears during the day or ophthalmic ointment at bedtime is recommended. The physician should also recommend protective eyewear such as sunglasses during the day. Eye patching or taping at night may be useful but could be harmful if applied too loosely or too tightly. Patients with vision loss or eye irritation should be referred to an ophthalmologist.¹⁹

Corticosteroids are recommended in the first 72 hours

In two randomized clinical trials (conducted by Sullivan et al²⁰ in 511 patients and Engström et al²¹ in 829 patients), prednisolone was found to be beneficial if started within 72 hours of symptom onset.

In a double-blind, randomized, placebo-controlled study of prednisone in 58 patients, those who received the drug recovered faster, although long-term outcomes in these patients were not significantly different than those in the control group.²² The American Academy of Neurology²³ rated this study as class II, ie, not meeting all of its criteria for the highest level of evidence, class I. Nevertheless, although prednisone lacks class I evidence, its use is recommended because it is a precursor to its active metabolite, prednisolone, which has been studied extensively.

The current guidelines of the American Academy of Neurology, updated in 2012, state, “For patients with new-onset Bell palsy, steroids are highly likely to be effective and should be offered to increase the probability of recovery of facial nerve function”²³ (level A evidence, ie, established as effective). They also concluded that adverse effects of corticosteroids were generally minor and temporary.

Similarly, the guidelines of the American Academy of Otolaryngology–Head and Neck Surgery, published in 2013, recommend oral corticosteroids within 72 hours of onset of symptoms of Bell palsy for patients age 16 and older.¹⁹ The recommendation is for a 10-day course of corticosteroids with at least 5 days at a high dose (prednisolone 50 mg orally daily for 10 days, or prednisone 60 mg orally daily for 5 days, followed by a 5-day taper). The benefit of corticosteroids after 72 hours is unclear (Table 3).¹⁹

Even though the guidelines recommend corticosteroids, the decision to use them in diabetic patients and pregnant women should be individualized. Discretion is advised, as not all patients with Bell palsy need to be treated. Most recover spontaneously, especially those with mild symptoms.

Antiviral therapy may offer modest benefit

Antiviral therapy has not been shown to be beneficial in Bell palsy, and current guidelines do not recommend oral antiviral therapy alone.¹⁹ However, an antiviral combined with a corticosteroid may offer modest benefit if started within 72 hours of symptom onset (level C evidence, ie, possibly effective).²³ Patients starting antiviral therapy should understand that its benefit has not been established.

Surgical decompression remains controversial

A Cochrane systematic review in 2011 found insufficient evidence regarding the safety and efficacy of surgical intervention in Bell palsy.²⁴ Surgery should be considered only for patients with complete paralysis with a greater than 90% reduction in motor amplitude on a nerve conduction study compared with the unaffected side, and absent volitional activity on needle examination.^19,25

Acupuncture: No recommendation

Currently, there is no recommendation for acupuncture in the treatment of Bell palsy.¹⁹ A recent randomized clinical trial suggests benefit from acupuncture combined with corticosteroids,²⁶ but high-quality studies to support its use are lacking.²⁶

Physical therapy: Insufficient evidence

There is insufficient evidence to show that physical therapy has benefit—or harm—in Bell palsy. However, some low-quality studies indicated that facial exercises and mime therapy may improve function in patients with moderate paralysis.²⁷

Follow-up

Instruct patients to call at 2 weeks to report progress of symptoms

Patients should be instructed to call at 2 weeks to report progress of symptoms and to be reevaluated within or at 1 month, with close attention to facial weakness and eye irritation. Further evaluation is needed if there has been no improvement, if symptoms have worsened, or if new symptoms have appeared.

The psychosocial impact of Bell palsy cannot be discounted, as the disfigurement can have negative implications for self-esteem and social relationships. Appropriate referral to an ophthalmologist, neurologist, otolaryngologist, social worker, or a plastic surgeon may be necessary.

COMPLICATIONS AND PROGNOSIS

Most patients with Bell palsy recover completely, but up to 30% have residual symptoms at 6 months.^14,20 Furthermore, although Bell palsy usually has a monophasic course, 7% to 12% of patients have a recurrence.^3,15

Long-term complications can include residual facial weakness, facial synkinesis, facial contracture, and facial spasm.^14,28 Incomplete eye closure may benefit from surgery (tarsorrhaphy or gold-weight implantation) to prevent corneal ulceration. Facial synkinesis is due to aberrant nerve regeneration and occurs in 15% to 20% of patients after recovery from Bell palsy.²⁹ Patients may describe tearing while chewing (“crocodile tears”), involuntary movement of the corners of the mouth with blinking, or ipsilateral eye-closing when the jaw opens (“jaw-winking”). Facial contracture, facial synkinesis, and facial spasm can be treated with botulinum toxin injection.³⁰

A 45-year-old woman presents with shortness of breath that has been progressively worsening for 3 weeks. She has no history of medical conditions and is taking no medications. Her blood pressure is 132/68 mm Hg, pulse 90 beats per minute, respirations 14 per minute, and oxygen saturation 95% on room air by pulse oximetry.

Physical examination reveals clear lung fields and no jugular venous distention or peripheral edema. However, she has a grade 3 of 6 continuous murmur audible over the entire precordium that does not change in intensity with respiration.

1. Which of the following is the likely cause of this patient’s cardiac murmur?

• Ventricular septal defect
• Atrial septal defect
• Ruptured sinus of Valsalva aneurysm
• Aortic regurgitation
• Patent ductus arteriosus
• Pulmonic stenosis

Table 1 summarizes the characteristics of the murmurs caused by these various cardiac defects.

Ventricular septal defect causes murmurs that are characteristically holosystolic and heard best at the lower left sternal border with radiation to the right lower sternal border, which overlies the defect.

The murmur of restrictive ventricular septal defect is most often holosystolic because the pressure difference between the ventricles is generated almost instantly at the onset of systole with a left-to-right shunt continuing throughout ventricular contraction. In contrast, nonrestrictive ventricular septal defects generally do not generate a murmur, since pressure is equalized across the defect. This left-to-right shunting may lead to right ventricular volume overload, resulting in delayed closure of the pulmonary valve and a widely split S2. Irreversible pulmonary hypertension with shunt reversal may occur if the defect remains untreated.¹

Atrial septal defect. The most characteristic feature of atrial septal defect is a fixed split S2 resulting from right ventricular volume overload due to left-to-right atrial shunting of blood flow. As flow is shunted from the left to the right atrium and subsequently into the right ventricle, ejection of excess blood through the pulmonary valve produces a midsystolic flow murmur, heard best over the left upper sternal border, that may radiate to the back.

Ruptured sinus of Valsalva aneurysm. The pressure is higher in the aorta than in the right atrium throughout the cardiac cycle, and if a shunt is created between the two structures by a ruptured sinus of Valsalva aneurysm, the blood flow across this shunt throughout the cardiac cycle produces a continuous murmur. In contrast, if a sinus of Valsalva aneurysm ruptures into the right ventricle, the murmur is accentuated in diastole and attenuated in systole, and is often associated with pounding pulses and a thrill along either the left or right sternal border.¹

Aortic regurgitation causes a diastolic murmur as blood flows retrograde into the left ventricle through the incompetent aortic valve. This murmur is usually described as a blowing, decrescendo murmur heard best at the third left intercostal space.

Patent ductus arteriosus is a communication between the descending thoracic aorta and the pulmonary artery that fails to close at birth. The hallmark murmur associated with this defect is a continuous “machine-like” murmur located at the upper left sternal border, often radiating down the left side of the sternum into the back. Of note, increasing the systemic pressure by the Valsalva maneuver or handgrip exercise will increase the diastolic component of the continuous murmur associated with ruptured sinus of Valsalva aneurysm, helping to differentiate it from patent ductus arteriosus.²

Pulmonic stenosis causes a systolic murmur heard best at the second intercostal space along the left sternal border and having a crescendo-decrescendo intensity and harsh quality. As the right ventricle takes longer to eject its blood volume through the stenotic pulmonary valve, the delay in closure between the aortic and pulmonary valve is widened, resulting in a significant splitting of the S2. In addition, any maneuver that increases preload will also increase the intensity of the murmur.³

Our patient has a murmur that is continuous, is heard across the entire precordium, and has no respiratory variation. These features are most consistent with a sinus of Valsalva aneurysm that has ruptured into the right atrium.

The 2008 update of the joint American College of Cardiology and American Heart Association guidelines⁴ recommends further evaluation of diastolic or continuous murmurs with echocardiography, as these murmurs are most often signs of a pathologic condition. In addition, echocardiography is warranted to evaluate grade 3 or higher systolic murmurs and those that are holosystolic.⁴

SINUS OF VALSALVA ANEURYSM

Sinus of Valsalva aneurysm is rare, with an incidence of 0.09% to 0.15%. From 65% to 85% are in the right coronary cusp, 10% to 30% are in the noncoronary cusp, and fewer than 5% are in the left coronary cusp.⁵

This condition is most often congenital, accounting for up to 3.5% of congenital cardiac anomalies, though it can be acquired. Formation of the aneurysm is generally related to weakening of elastic fibers and muscular tissues that progresses over time.

Many cases of sinus of Valsalva aneurysm are associated with additional cardiac defects.¹ Ventricular septal defect is the most common coexisting congenital anomaly, occurring in up to 53% of patients and frequently associated with aneurysms involving the right coronary cusp and with sinus of Valsalva aneurysm.⁶ Other congenital anomalies often accompanying sinus of Valsalva aneurysm include pulmonary stenosis, atrial septal defect, bicuspid aortic valve, tetralogy of Fallot, patent ductus arteriosus, coarctation of the aorta, and subaortic stenosis. Another associated condition is aortic regurgitation, for which more than half of affected patients eventually require aortic valve replacement.²

Acquired sinus of Valsalva aneurysm can be the result of endocarditis, trauma, surgery, cardiac catheterization, or inflammatory or degenerative processes including, rarely, tertiary syphilis.³

Sinus of Valsalva aneurysm often remains asymptomatic, but symptoms may arise if the aneurysm ruptures, resulting in intracardiac shunting or aneurysm-associated compression of adjacent cardiac structures such as coronary arteries. Rupture may be spontaneous, secondary to chest trauma or excess exertion, or iatrogenic.

Imaging studies such as echocardiography, cardiac computed tomography, and cardiac magnetic resonance imaging are essential in diagnosing and managing sinus of Valsalva aneurysm and identifying coexisting cardiac anomalies.

Rupture occurs most commonly into the right ventricle, followed in frequency by the right atrium or left atrium. Once rupture occurs, median survival is 1 to 2 years if left untreated, with death often secondary to congestive heart failure or infective endocarditis.⁷

Surgery remains the preferred approach to the treatment of ruptured sinus of Valsalva aneurysm. Operative risk is reasonably low and long-term outcomes are good. The appropriate therapy for unruptured and asymptomatic sinus of Valsalva aneurysm remains less clear.

Successful transcatheter closure of ruptured sinus of Valsalva aneurysm has been described using Amplatzer devices, a procedure that avoids sternotomy and cardiopulmonary bypass. Despite advances in percutaneous techniques, open surgery with or without aortic valve replacement remains the current standard of care.⁸

BACK TO OUR PATIENT

In the case described above, the initial diagnostic study done to evaluate the patient’s dyspnea and murmur was transthoracic echocardiography, which demonstrated a relatively preserved ejection fraction with mild aortic regurgitation and an aneurysmal structure extending from the aortic root toward the right atrium.

Transesophageal echocardiography confirmed this finding (Figure 1). Cross-sectional imaging of the aortic valve (Figure 2) showed the aneurysm arising from the noncoronary cusp and communicating with the right atrium. Color flow Doppler (Figure 3) confirmed continuous flow between the aneurysmal sinus and right atrium throughout the cardiac cycle, consistent with the continuous murmur noted on physical examination.

The aneurysm was also noted on aortography (Figure 4) obtained before the patient underwent surgery to correct it. The surgery was successful, no complications occurred, and the murmur and associated dyspnea had completely resolved at subsequent follow-up.

This case highlights the importance of imaging studies such as echocardiography in diagnosing and managing sinus of Valsalva aneurysm, and also the importance of physical examination in guiding the diagnostic evaluation and differentiating this condition from other cardiac disorders.

A 45-year-old woman presents with shortness of breath that has been progressively worsening for 3 weeks. She has no history of medical conditions and is taking no medications. Her blood pressure is 132/68 mm Hg, pulse 90 beats per minute, respirations 14 per minute, and oxygen saturation 95% on room air by pulse oximetry.

Physical examination reveals clear lung fields and no jugular venous distention or peripheral edema. However, she has a grade 3 of 6 continuous murmur audible over the entire precordium that does not change in intensity with respiration.

1. Which of the following is the likely cause of this patient’s cardiac murmur?

• Ventricular septal defect
• Atrial septal defect
• Ruptured sinus of Valsalva aneurysm
• Aortic regurgitation
• Patent ductus arteriosus
• Pulmonic stenosis

Table 1 summarizes the characteristics of the murmurs caused by these various cardiac defects.

Ventricular septal defect causes murmurs that are characteristically holosystolic and heard best at the lower left sternal border with radiation to the right lower sternal border, which overlies the defect.

The murmur of restrictive ventricular septal defect is most often holosystolic because the pressure difference between the ventricles is generated almost instantly at the onset of systole with a left-to-right shunt continuing throughout ventricular contraction. In contrast, nonrestrictive ventricular septal defects generally do not generate a murmur, since pressure is equalized across the defect. This left-to-right shunting may lead to right ventricular volume overload, resulting in delayed closure of the pulmonary valve and a widely split S2. Irreversible pulmonary hypertension with shunt reversal may occur if the defect remains untreated.¹

Atrial septal defect. The most characteristic feature of atrial septal defect is a fixed split S2 resulting from right ventricular volume overload due to left-to-right atrial shunting of blood flow. As flow is shunted from the left to the right atrium and subsequently into the right ventricle, ejection of excess blood through the pulmonary valve produces a midsystolic flow murmur, heard best over the left upper sternal border, that may radiate to the back.

Ruptured sinus of Valsalva aneurysm. The pressure is higher in the aorta than in the right atrium throughout the cardiac cycle, and if a shunt is created between the two structures by a ruptured sinus of Valsalva aneurysm, the blood flow across this shunt throughout the cardiac cycle produces a continuous murmur. In contrast, if a sinus of Valsalva aneurysm ruptures into the right ventricle, the murmur is accentuated in diastole and attenuated in systole, and is often associated with pounding pulses and a thrill along either the left or right sternal border.¹

Aortic regurgitation causes a diastolic murmur as blood flows retrograde into the left ventricle through the incompetent aortic valve. This murmur is usually described as a blowing, decrescendo murmur heard best at the third left intercostal space.

Patent ductus arteriosus is a communication between the descending thoracic aorta and the pulmonary artery that fails to close at birth. The hallmark murmur associated with this defect is a continuous “machine-like” murmur located at the upper left sternal border, often radiating down the left side of the sternum into the back. Of note, increasing the systemic pressure by the Valsalva maneuver or handgrip exercise will increase the diastolic component of the continuous murmur associated with ruptured sinus of Valsalva aneurysm, helping to differentiate it from patent ductus arteriosus.²

Pulmonic stenosis causes a systolic murmur heard best at the second intercostal space along the left sternal border and having a crescendo-decrescendo intensity and harsh quality. As the right ventricle takes longer to eject its blood volume through the stenotic pulmonary valve, the delay in closure between the aortic and pulmonary valve is widened, resulting in a significant splitting of the S2. In addition, any maneuver that increases preload will also increase the intensity of the murmur.³

Our patient has a murmur that is continuous, is heard across the entire precordium, and has no respiratory variation. These features are most consistent with a sinus of Valsalva aneurysm that has ruptured into the right atrium.

The 2008 update of the joint American College of Cardiology and American Heart Association guidelines⁴ recommends further evaluation of diastolic or continuous murmurs with echocardiography, as these murmurs are most often signs of a pathologic condition. In addition, echocardiography is warranted to evaluate grade 3 or higher systolic murmurs and those that are holosystolic.⁴

SINUS OF VALSALVA ANEURYSM

Sinus of Valsalva aneurysm is rare, with an incidence of 0.09% to 0.15%. From 65% to 85% are in the right coronary cusp, 10% to 30% are in the noncoronary cusp, and fewer than 5% are in the left coronary cusp.⁵

This condition is most often congenital, accounting for up to 3.5% of congenital cardiac anomalies, though it can be acquired. Formation of the aneurysm is generally related to weakening of elastic fibers and muscular tissues that progresses over time.

Many cases of sinus of Valsalva aneurysm are associated with additional cardiac defects.¹ Ventricular septal defect is the most common coexisting congenital anomaly, occurring in up to 53% of patients and frequently associated with aneurysms involving the right coronary cusp and with sinus of Valsalva aneurysm.⁶ Other congenital anomalies often accompanying sinus of Valsalva aneurysm include pulmonary stenosis, atrial septal defect, bicuspid aortic valve, tetralogy of Fallot, patent ductus arteriosus, coarctation of the aorta, and subaortic stenosis. Another associated condition is aortic regurgitation, for which more than half of affected patients eventually require aortic valve replacement.²

Acquired sinus of Valsalva aneurysm can be the result of endocarditis, trauma, surgery, cardiac catheterization, or inflammatory or degenerative processes including, rarely, tertiary syphilis.³

Sinus of Valsalva aneurysm often remains asymptomatic, but symptoms may arise if the aneurysm ruptures, resulting in intracardiac shunting or aneurysm-associated compression of adjacent cardiac structures such as coronary arteries. Rupture may be spontaneous, secondary to chest trauma or excess exertion, or iatrogenic.

Imaging studies such as echocardiography, cardiac computed tomography, and cardiac magnetic resonance imaging are essential in diagnosing and managing sinus of Valsalva aneurysm and identifying coexisting cardiac anomalies.

Rupture occurs most commonly into the right ventricle, followed in frequency by the right atrium or left atrium. Once rupture occurs, median survival is 1 to 2 years if left untreated, with death often secondary to congestive heart failure or infective endocarditis.⁷

Surgery remains the preferred approach to the treatment of ruptured sinus of Valsalva aneurysm. Operative risk is reasonably low and long-term outcomes are good. The appropriate therapy for unruptured and asymptomatic sinus of Valsalva aneurysm remains less clear.

Successful transcatheter closure of ruptured sinus of Valsalva aneurysm has been described using Amplatzer devices, a procedure that avoids sternotomy and cardiopulmonary bypass. Despite advances in percutaneous techniques, open surgery with or without aortic valve replacement remains the current standard of care.⁸

BACK TO OUR PATIENT

In the case described above, the initial diagnostic study done to evaluate the patient’s dyspnea and murmur was transthoracic echocardiography, which demonstrated a relatively preserved ejection fraction with mild aortic regurgitation and an aneurysmal structure extending from the aortic root toward the right atrium.

Transesophageal echocardiography confirmed this finding (Figure 1). Cross-sectional imaging of the aortic valve (Figure 2) showed the aneurysm arising from the noncoronary cusp and communicating with the right atrium. Color flow Doppler (Figure 3) confirmed continuous flow between the aneurysmal sinus and right atrium throughout the cardiac cycle, consistent with the continuous murmur noted on physical examination.

The aneurysm was also noted on aortography (Figure 4) obtained before the patient underwent surgery to correct it. The surgery was successful, no complications occurred, and the murmur and associated dyspnea had completely resolved at subsequent follow-up.

This case highlights the importance of imaging studies such as echocardiography in diagnosing and managing sinus of Valsalva aneurysm, and also the importance of physical examination in guiding the diagnostic evaluation and differentiating this condition from other cardiac disorders.

A 45-year-old woman presents with shortness of breath that has been progressively worsening for 3 weeks. She has no history of medical conditions and is taking no medications. Her blood pressure is 132/68 mm Hg, pulse 90 beats per minute, respirations 14 per minute, and oxygen saturation 95% on room air by pulse oximetry.

Physical examination reveals clear lung fields and no jugular venous distention or peripheral edema. However, she has a grade 3 of 6 continuous murmur audible over the entire precordium that does not change in intensity with respiration.

1. Which of the following is the likely cause of this patient’s cardiac murmur?

• Ventricular septal defect
• Atrial septal defect
• Ruptured sinus of Valsalva aneurysm
• Aortic regurgitation
• Patent ductus arteriosus
• Pulmonic stenosis

Table 1 summarizes the characteristics of the murmurs caused by these various cardiac defects.

Ventricular septal defect causes murmurs that are characteristically holosystolic and heard best at the lower left sternal border with radiation to the right lower sternal border, which overlies the defect.

The murmur of restrictive ventricular septal defect is most often holosystolic because the pressure difference between the ventricles is generated almost instantly at the onset of systole with a left-to-right shunt continuing throughout ventricular contraction. In contrast, nonrestrictive ventricular septal defects generally do not generate a murmur, since pressure is equalized across the defect. This left-to-right shunting may lead to right ventricular volume overload, resulting in delayed closure of the pulmonary valve and a widely split S2. Irreversible pulmonary hypertension with shunt reversal may occur if the defect remains untreated.¹

Atrial septal defect. The most characteristic feature of atrial septal defect is a fixed split S2 resulting from right ventricular volume overload due to left-to-right atrial shunting of blood flow. As flow is shunted from the left to the right atrium and subsequently into the right ventricle, ejection of excess blood through the pulmonary valve produces a midsystolic flow murmur, heard best over the left upper sternal border, that may radiate to the back.

Ruptured sinus of Valsalva aneurysm. The pressure is higher in the aorta than in the right atrium throughout the cardiac cycle, and if a shunt is created between the two structures by a ruptured sinus of Valsalva aneurysm, the blood flow across this shunt throughout the cardiac cycle produces a continuous murmur. In contrast, if a sinus of Valsalva aneurysm ruptures into the right ventricle, the murmur is accentuated in diastole and attenuated in systole, and is often associated with pounding pulses and a thrill along either the left or right sternal border.¹

Aortic regurgitation causes a diastolic murmur as blood flows retrograde into the left ventricle through the incompetent aortic valve. This murmur is usually described as a blowing, decrescendo murmur heard best at the third left intercostal space.

Patent ductus arteriosus is a communication between the descending thoracic aorta and the pulmonary artery that fails to close at birth. The hallmark murmur associated with this defect is a continuous “machine-like” murmur located at the upper left sternal border, often radiating down the left side of the sternum into the back. Of note, increasing the systemic pressure by the Valsalva maneuver or handgrip exercise will increase the diastolic component of the continuous murmur associated with ruptured sinus of Valsalva aneurysm, helping to differentiate it from patent ductus arteriosus.²

Pulmonic stenosis causes a systolic murmur heard best at the second intercostal space along the left sternal border and having a crescendo-decrescendo intensity and harsh quality. As the right ventricle takes longer to eject its blood volume through the stenotic pulmonary valve, the delay in closure between the aortic and pulmonary valve is widened, resulting in a significant splitting of the S2. In addition, any maneuver that increases preload will also increase the intensity of the murmur.³

Our patient has a murmur that is continuous, is heard across the entire precordium, and has no respiratory variation. These features are most consistent with a sinus of Valsalva aneurysm that has ruptured into the right atrium.

The 2008 update of the joint American College of Cardiology and American Heart Association guidelines⁴ recommends further evaluation of diastolic or continuous murmurs with echocardiography, as these murmurs are most often signs of a pathologic condition. In addition, echocardiography is warranted to evaluate grade 3 or higher systolic murmurs and those that are holosystolic.⁴

SINUS OF VALSALVA ANEURYSM

Sinus of Valsalva aneurysm is rare, with an incidence of 0.09% to 0.15%. From 65% to 85% are in the right coronary cusp, 10% to 30% are in the noncoronary cusp, and fewer than 5% are in the left coronary cusp.⁵

This condition is most often congenital, accounting for up to 3.5% of congenital cardiac anomalies, though it can be acquired. Formation of the aneurysm is generally related to weakening of elastic fibers and muscular tissues that progresses over time.

Many cases of sinus of Valsalva aneurysm are associated with additional cardiac defects.¹ Ventricular septal defect is the most common coexisting congenital anomaly, occurring in up to 53% of patients and frequently associated with aneurysms involving the right coronary cusp and with sinus of Valsalva aneurysm.⁶ Other congenital anomalies often accompanying sinus of Valsalva aneurysm include pulmonary stenosis, atrial septal defect, bicuspid aortic valve, tetralogy of Fallot, patent ductus arteriosus, coarctation of the aorta, and subaortic stenosis. Another associated condition is aortic regurgitation, for which more than half of affected patients eventually require aortic valve replacement.²

Acquired sinus of Valsalva aneurysm can be the result of endocarditis, trauma, surgery, cardiac catheterization, or inflammatory or degenerative processes including, rarely, tertiary syphilis.³

Sinus of Valsalva aneurysm often remains asymptomatic, but symptoms may arise if the aneurysm ruptures, resulting in intracardiac shunting or aneurysm-associated compression of adjacent cardiac structures such as coronary arteries. Rupture may be spontaneous, secondary to chest trauma or excess exertion, or iatrogenic.

Imaging studies such as echocardiography, cardiac computed tomography, and cardiac magnetic resonance imaging are essential in diagnosing and managing sinus of Valsalva aneurysm and identifying coexisting cardiac anomalies.

Rupture occurs most commonly into the right ventricle, followed in frequency by the right atrium or left atrium. Once rupture occurs, median survival is 1 to 2 years if left untreated, with death often secondary to congestive heart failure or infective endocarditis.⁷

Surgery remains the preferred approach to the treatment of ruptured sinus of Valsalva aneurysm. Operative risk is reasonably low and long-term outcomes are good. The appropriate therapy for unruptured and asymptomatic sinus of Valsalva aneurysm remains less clear.

Successful transcatheter closure of ruptured sinus of Valsalva aneurysm has been described using Amplatzer devices, a procedure that avoids sternotomy and cardiopulmonary bypass. Despite advances in percutaneous techniques, open surgery with or without aortic valve replacement remains the current standard of care.⁸

BACK TO OUR PATIENT

In the case described above, the initial diagnostic study done to evaluate the patient’s dyspnea and murmur was transthoracic echocardiography, which demonstrated a relatively preserved ejection fraction with mild aortic regurgitation and an aneurysmal structure extending from the aortic root toward the right atrium.

Transesophageal echocardiography confirmed this finding (Figure 1). Cross-sectional imaging of the aortic valve (Figure 2) showed the aneurysm arising from the noncoronary cusp and communicating with the right atrium. Color flow Doppler (Figure 3) confirmed continuous flow between the aneurysmal sinus and right atrium throughout the cardiac cycle, consistent with the continuous murmur noted on physical examination.

The aneurysm was also noted on aortography (Figure 4) obtained before the patient underwent surgery to correct it. The surgery was successful, no complications occurred, and the murmur and associated dyspnea had completely resolved at subsequent follow-up.

This case highlights the importance of imaging studies such as echocardiography in diagnosing and managing sinus of Valsalva aneurysm, and also the importance of physical examination in guiding the diagnostic evaluation and differentiating this condition from other cardiac disorders.

A 76-year-old woman visiting from Ethiopia presented for further evaluation of concomitant iron and vitamin B₁₂ deficiency anemia that had developed over the previous 6 months. During that time, she had complained of ongoing fatigue and increasing paresthesias in the hands and feet.

At presentation, her hemoglobin concentration was 7.8 g/dL (reference range 11.5–15), with a mean corpuscular volume of 81.8 fL (81.5–97.0). These values were down from her baseline hemoglobin of 12 g/dL and corpuscular volume of 85.8 recorded more than 1 year ago. Serum studies showed an iron concentration of 21 µg/dL (37–170), ferritin 3 ng/mL (10–107), and percent saturation of transferrin 5% (20%–55%). Also noted was a low vitamin B₁₂ level of 108 pg/mL (180–1,241 pg/mL). She had no overt signs of gastrointestinal blood loss. She did not report altered bowel habits or use of nonsteroidal anti-inflammatory medications.

Given her country of origin, she was sent for initial stool testing for ova and parasites, which was unrevealing.

She underwent esophagogastroduodenoscopy and colonoscopy, which revealed no underlying cause of her iron deficiency or vitamin B₁₂ insufficiency. But further evaluation with capsule endoscopy showed evidence of a tapeworm in the distal duodenum (Figure 1).

She was given praziquantel in a single oral dose of 10 mg/kg. Repeat stool culture 1 month later showed no evidence of tapeworm infection, and at follow-up 3 months later, her hemoglobin had recovered to 13.2 g/dL with a corpuscular volume of 87.6 fL and no residual vitamin B₁₂ or iron deficiency. She reported complete resolution of fatigue and of paresthesias of the hands and feet.

DIPHYLLOBOTHRIUM LATUM

The appearance on capsule endoscopy indicated Diphyllobothrium latum as the likely parasite. This tapeworm is acquired by ingesting undercooked or raw fish. Infection is most common in Northern Europe but has been reported in Africa.¹

As it grows, the tapeworm develops chains of segments and can reach a length of 1 to 15 meters.¹ In humans, it typically resides in the small intestine. Most patients are asymptomatic or have moderate nonspecific symptoms such as abdominal pain and diarrhea. A key differentiating aspect of D latum infection is vitamin B₁₂ deficiency caused by consumption of the vitamin by the parasite, as well as by parasite-mediated dissociation of the vitamin B₁₂-intrinsic factor complex, thus making the vitamin unavailable to the host.

Up to 40% of people infected with D latum develop low levels of vitamin B₁₂, and 2% develop symptomatic megaloblastic anemia.² Iron deficiency anemia is uncommon but has been reported.³ In our patient, the concomitant iron deficiency was probably secondary to involvement of the duodenum, where a significant amount of dietary iron is absorbed.

The diagnosis is typically established by stool testing for ova and parasites. When stool samples do not reveal a cause of the symptoms, as in this patient, endoscopy can be used. Capsule endoscopy has not been widely used in the diagnosis of intestinal helminth infection, although reports exist describing the use of capsule endoscopy to detect intestinal parasites. Notably, as in this case, intestinal parasite infection is occasionally found during investigations of anemia and vitamin deficiencies of unknown cause.⁴

As in our patient, treatment of infection with this species of tapeworm typically involves a single oral dose of praziquantel; this off-label use has been shown to lead to resolution of symptoms in nearly all patients treated.⁵

A 76-year-old woman visiting from Ethiopia presented for further evaluation of concomitant iron and vitamin B₁₂ deficiency anemia that had developed over the previous 6 months. During that time, she had complained of ongoing fatigue and increasing paresthesias in the hands and feet.

At presentation, her hemoglobin concentration was 7.8 g/dL (reference range 11.5–15), with a mean corpuscular volume of 81.8 fL (81.5–97.0). These values were down from her baseline hemoglobin of 12 g/dL and corpuscular volume of 85.8 recorded more than 1 year ago. Serum studies showed an iron concentration of 21 µg/dL (37–170), ferritin 3 ng/mL (10–107), and percent saturation of transferrin 5% (20%–55%). Also noted was a low vitamin B₁₂ level of 108 pg/mL (180–1,241 pg/mL). She had no overt signs of gastrointestinal blood loss. She did not report altered bowel habits or use of nonsteroidal anti-inflammatory medications.

Given her country of origin, she was sent for initial stool testing for ova and parasites, which was unrevealing.

She underwent esophagogastroduodenoscopy and colonoscopy, which revealed no underlying cause of her iron deficiency or vitamin B₁₂ insufficiency. But further evaluation with capsule endoscopy showed evidence of a tapeworm in the distal duodenum (Figure 1).

She was given praziquantel in a single oral dose of 10 mg/kg. Repeat stool culture 1 month later showed no evidence of tapeworm infection, and at follow-up 3 months later, her hemoglobin had recovered to 13.2 g/dL with a corpuscular volume of 87.6 fL and no residual vitamin B₁₂ or iron deficiency. She reported complete resolution of fatigue and of paresthesias of the hands and feet.

DIPHYLLOBOTHRIUM LATUM

The appearance on capsule endoscopy indicated Diphyllobothrium latum as the likely parasite. This tapeworm is acquired by ingesting undercooked or raw fish. Infection is most common in Northern Europe but has been reported in Africa.¹

As it grows, the tapeworm develops chains of segments and can reach a length of 1 to 15 meters.¹ In humans, it typically resides in the small intestine. Most patients are asymptomatic or have moderate nonspecific symptoms such as abdominal pain and diarrhea. A key differentiating aspect of D latum infection is vitamin B₁₂ deficiency caused by consumption of the vitamin by the parasite, as well as by parasite-mediated dissociation of the vitamin B₁₂-intrinsic factor complex, thus making the vitamin unavailable to the host.

Up to 40% of people infected with D latum develop low levels of vitamin B₁₂, and 2% develop symptomatic megaloblastic anemia.² Iron deficiency anemia is uncommon but has been reported.³ In our patient, the concomitant iron deficiency was probably secondary to involvement of the duodenum, where a significant amount of dietary iron is absorbed.

The diagnosis is typically established by stool testing for ova and parasites. When stool samples do not reveal a cause of the symptoms, as in this patient, endoscopy can be used. Capsule endoscopy has not been widely used in the diagnosis of intestinal helminth infection, although reports exist describing the use of capsule endoscopy to detect intestinal parasites. Notably, as in this case, intestinal parasite infection is occasionally found during investigations of anemia and vitamin deficiencies of unknown cause.⁴

As in our patient, treatment of infection with this species of tapeworm typically involves a single oral dose of praziquantel; this off-label use has been shown to lead to resolution of symptoms in nearly all patients treated.⁵

A 76-year-old woman visiting from Ethiopia presented for further evaluation of concomitant iron and vitamin B₁₂ deficiency anemia that had developed over the previous 6 months. During that time, she had complained of ongoing fatigue and increasing paresthesias in the hands and feet.

At presentation, her hemoglobin concentration was 7.8 g/dL (reference range 11.5–15), with a mean corpuscular volume of 81.8 fL (81.5–97.0). These values were down from her baseline hemoglobin of 12 g/dL and corpuscular volume of 85.8 recorded more than 1 year ago. Serum studies showed an iron concentration of 21 µg/dL (37–170), ferritin 3 ng/mL (10–107), and percent saturation of transferrin 5% (20%–55%). Also noted was a low vitamin B₁₂ level of 108 pg/mL (180–1,241 pg/mL). She had no overt signs of gastrointestinal blood loss. She did not report altered bowel habits or use of nonsteroidal anti-inflammatory medications.

Given her country of origin, she was sent for initial stool testing for ova and parasites, which was unrevealing.

She underwent esophagogastroduodenoscopy and colonoscopy, which revealed no underlying cause of her iron deficiency or vitamin B₁₂ insufficiency. But further evaluation with capsule endoscopy showed evidence of a tapeworm in the distal duodenum (Figure 1).

She was given praziquantel in a single oral dose of 10 mg/kg. Repeat stool culture 1 month later showed no evidence of tapeworm infection, and at follow-up 3 months later, her hemoglobin had recovered to 13.2 g/dL with a corpuscular volume of 87.6 fL and no residual vitamin B₁₂ or iron deficiency. She reported complete resolution of fatigue and of paresthesias of the hands and feet.

DIPHYLLOBOTHRIUM LATUM

The appearance on capsule endoscopy indicated Diphyllobothrium latum as the likely parasite. This tapeworm is acquired by ingesting undercooked or raw fish. Infection is most common in Northern Europe but has been reported in Africa.¹

As it grows, the tapeworm develops chains of segments and can reach a length of 1 to 15 meters.¹ In humans, it typically resides in the small intestine. Most patients are asymptomatic or have moderate nonspecific symptoms such as abdominal pain and diarrhea. A key differentiating aspect of D latum infection is vitamin B₁₂ deficiency caused by consumption of the vitamin by the parasite, as well as by parasite-mediated dissociation of the vitamin B₁₂-intrinsic factor complex, thus making the vitamin unavailable to the host.

Up to 40% of people infected with D latum develop low levels of vitamin B₁₂, and 2% develop symptomatic megaloblastic anemia.² Iron deficiency anemia is uncommon but has been reported.³ In our patient, the concomitant iron deficiency was probably secondary to involvement of the duodenum, where a significant amount of dietary iron is absorbed.

The diagnosis is typically established by stool testing for ova and parasites. When stool samples do not reveal a cause of the symptoms, as in this patient, endoscopy can be used. Capsule endoscopy has not been widely used in the diagnosis of intestinal helminth infection, although reports exist describing the use of capsule endoscopy to detect intestinal parasites. Notably, as in this case, intestinal parasite infection is occasionally found during investigations of anemia and vitamin deficiencies of unknown cause.⁴

As in our patient, treatment of infection with this species of tapeworm typically involves a single oral dose of praziquantel; this off-label use has been shown to lead to resolution of symptoms in nearly all patients treated.⁵

A 62-year-old man was admitted to the intensive care unit with esophageal variceal bleeding. He had a long history of alcohol abuse with secondary cirrhosis, with a Child-Pugh score of 11 on a scale of 15 (class C—the most severe) at presentation. He also had a history of uncomplicated umbilical hernia, 6 cm in diameter without overlying trophic skin alterations.

Treatment with somatostatin, endoscopic band ligation, and prophylactic antibiotics was initiated for the variceal bleeding. The next day, he was transferred to the hepatology floor. His condition stabilized during the next week, but then he abruptly became diaphoretic and less talkative. Physical examination revealed a painful and irreducible umbilical hernia (Figure 1). He was rushed for umbilical hernia repair with resection of a necrotic segment of small bowel. His recovery after surgery was uneventful, and he was eventually discharged.

UMBILICAL HERNIA AND CIRRHOSIS

Umbilical hernia is common in cirrhotic patients suffering from ascites, with a prevalence up to 20%, which is 10 times higher than in the general population.¹ Ascites is the major predisposing factor since it causes muscle wasting and increases intra-abdominal pressure.

A unique feature of cirrhosis is low physiologic reserve, which increases the risk of death from complications of umbilical hernia and makes the patient more vulnerable to perioperative complications during repair. Because of the high operative risk, umbilical hernia repair has traditionally been reserved for the most complicated cases, such as strangulation of the bowel or rupture of the skin with leakage of ascitic fluid.^2,3 Many patients are thus managed conservatively, with watchful waiting.

However, the natural course of umbilical hernia tends toward complications (eg, bowel incarceration, rupture of the overlying skin), which necessitate urgent repair.⁴ The risk of death with hernia repair in this urgent setting is seven times higher than for elective hernia repair in cirrhotic patients.⁵ More recent data indicate that elective repair in patients with well-compensated cirrhosis carries complication and mortality rates similar to those in noncirrhotic patients.^5–8 Therefore, patients who should undergo umbilical hernia repair are not only those with complicated umbilical hernia (strangulation or ascites leak), but also those with well-compensated cirrhosis at risk of complications.

Factors that pose a particularly high risk of complications of repair are large hernia (> 5 cm), hernia associated with pain, intermittent incarceration, and trophic alterations of the overlying skin.¹ In these patients, elective repair should be considered if hepatic function is preserved, if ascites is well managed (sodium restriction, diuretics, and sometimes even preoperative transjugular intrahepatic portosystemic shunt placement), and if the patient is not expected to undergo liver transplantation in the near future. If liver transplantation is anticipated in the short term, umbilical hernia can be managed concomitantly. Management of ascites after umbilical hernia repair is essential for prevention of recurrence.

A 62-year-old man was admitted to the intensive care unit with esophageal variceal bleeding. He had a long history of alcohol abuse with secondary cirrhosis, with a Child-Pugh score of 11 on a scale of 15 (class C—the most severe) at presentation. He also had a history of uncomplicated umbilical hernia, 6 cm in diameter without overlying trophic skin alterations.

Treatment with somatostatin, endoscopic band ligation, and prophylactic antibiotics was initiated for the variceal bleeding. The next day, he was transferred to the hepatology floor. His condition stabilized during the next week, but then he abruptly became diaphoretic and less talkative. Physical examination revealed a painful and irreducible umbilical hernia (Figure 1). He was rushed for umbilical hernia repair with resection of a necrotic segment of small bowel. His recovery after surgery was uneventful, and he was eventually discharged.

UMBILICAL HERNIA AND CIRRHOSIS

Umbilical hernia is common in cirrhotic patients suffering from ascites, with a prevalence up to 20%, which is 10 times higher than in the general population.¹ Ascites is the major predisposing factor since it causes muscle wasting and increases intra-abdominal pressure.

A unique feature of cirrhosis is low physiologic reserve, which increases the risk of death from complications of umbilical hernia and makes the patient more vulnerable to perioperative complications during repair. Because of the high operative risk, umbilical hernia repair has traditionally been reserved for the most complicated cases, such as strangulation of the bowel or rupture of the skin with leakage of ascitic fluid.^2,3 Many patients are thus managed conservatively, with watchful waiting.

However, the natural course of umbilical hernia tends toward complications (eg, bowel incarceration, rupture of the overlying skin), which necessitate urgent repair.⁴ The risk of death with hernia repair in this urgent setting is seven times higher than for elective hernia repair in cirrhotic patients.⁵ More recent data indicate that elective repair in patients with well-compensated cirrhosis carries complication and mortality rates similar to those in noncirrhotic patients.^5–8 Therefore, patients who should undergo umbilical hernia repair are not only those with complicated umbilical hernia (strangulation or ascites leak), but also those with well-compensated cirrhosis at risk of complications.

Factors that pose a particularly high risk of complications of repair are large hernia (> 5 cm), hernia associated with pain, intermittent incarceration, and trophic alterations of the overlying skin.¹ In these patients, elective repair should be considered if hepatic function is preserved, if ascites is well managed (sodium restriction, diuretics, and sometimes even preoperative transjugular intrahepatic portosystemic shunt placement), and if the patient is not expected to undergo liver transplantation in the near future. If liver transplantation is anticipated in the short term, umbilical hernia can be managed concomitantly. Management of ascites after umbilical hernia repair is essential for prevention of recurrence.

A 62-year-old man was admitted to the intensive care unit with esophageal variceal bleeding. He had a long history of alcohol abuse with secondary cirrhosis, with a Child-Pugh score of 11 on a scale of 15 (class C—the most severe) at presentation. He also had a history of uncomplicated umbilical hernia, 6 cm in diameter without overlying trophic skin alterations.

Treatment with somatostatin, endoscopic band ligation, and prophylactic antibiotics was initiated for the variceal bleeding. The next day, he was transferred to the hepatology floor. His condition stabilized during the next week, but then he abruptly became diaphoretic and less talkative. Physical examination revealed a painful and irreducible umbilical hernia (Figure 1). He was rushed for umbilical hernia repair with resection of a necrotic segment of small bowel. His recovery after surgery was uneventful, and he was eventually discharged.

UMBILICAL HERNIA AND CIRRHOSIS

Umbilical hernia is common in cirrhotic patients suffering from ascites, with a prevalence up to 20%, which is 10 times higher than in the general population.¹ Ascites is the major predisposing factor since it causes muscle wasting and increases intra-abdominal pressure.

A unique feature of cirrhosis is low physiologic reserve, which increases the risk of death from complications of umbilical hernia and makes the patient more vulnerable to perioperative complications during repair. Because of the high operative risk, umbilical hernia repair has traditionally been reserved for the most complicated cases, such as strangulation of the bowel or rupture of the skin with leakage of ascitic fluid.^2,3 Many patients are thus managed conservatively, with watchful waiting.

However, the natural course of umbilical hernia tends toward complications (eg, bowel incarceration, rupture of the overlying skin), which necessitate urgent repair.⁴ The risk of death with hernia repair in this urgent setting is seven times higher than for elective hernia repair in cirrhotic patients.⁵ More recent data indicate that elective repair in patients with well-compensated cirrhosis carries complication and mortality rates similar to those in noncirrhotic patients.^5–8 Therefore, patients who should undergo umbilical hernia repair are not only those with complicated umbilical hernia (strangulation or ascites leak), but also those with well-compensated cirrhosis at risk of complications.

Factors that pose a particularly high risk of complications of repair are large hernia (> 5 cm), hernia associated with pain, intermittent incarceration, and trophic alterations of the overlying skin.¹ In these patients, elective repair should be considered if hepatic function is preserved, if ascites is well managed (sodium restriction, diuretics, and sometimes even preoperative transjugular intrahepatic portosystemic shunt placement), and if the patient is not expected to undergo liver transplantation in the near future. If liver transplantation is anticipated in the short term, umbilical hernia can be managed concomitantly. Management of ascites after umbilical hernia repair is essential for prevention of recurrence.

A 49-year-old woman with a history of depression, bipolar disorder, and chronic back pain was brought to the emergency department unresponsive after having taken an unknown quantity of amitriptyline tablets.

On arrival, she was comatose, with a score of 3 (the lowest possible score) on the 15-point Glasgow Coma Scale. Her blood pressure was 65/22 mm Hg, heart rate 121 beats per minute, respiratory rate 14 per minute, and oxygen saturation 88% on room air. The rest of the initial physical examination was normal.

She was immediately intubated, put on mechanical ventilation, and given an infusion of a 1-L bolus of normal saline and 50 mmol (1 mmol/kg) of sodium bicarbonate. Norepinephrine infusion was started. Gastric lavage was not done.

Results of initial laboratory testing showed a serum potassium of 2.9 mmol/L (reference range 3.5–5.0) and a serum magnesium of 1.6 mmol/L (1.7–2.6), which were corrected with infusion of 60 mmol of potassium chloride and 2 g of magnesium sulfate. The serum amitriptyline measurement was ordered at the time of her presentation to the emergency department.

Arterial blood gas analysis showed:

• pH 7.15 (normal range 7.35–7.45)
• Paco₂ 66 mm Hg (34–46)
• Pao₂ 229 mm Hg (85–95)
• Bicarbonate 22 mmol/L (22–26).

The initial electrocardiogram (ECG) (Figure 1) showed regular wide-complex tachycardia with no definite right or left bundle branch block morphology, no discernible P waves, a QRS duration of 198 msec, right axis deviation, and no Brugada criteria to suggest ventricular tachycardia.

She remained hypotensive, with regular wide-complex tachycardia on the ECG. She was given an additional 1-L bolus of normal saline and 100 mmol (2 mmol/kg) of sodium bicarbonate, and within 1 minute the wide-complex tachycardia resolved to narrow-complex sinus tachycardia (Figure 2). At this point, an infusion of 150 mmol/L of sodium bicarbonate in dextrose 5% in water was started, with serial ECGs to monitor the QRS duration and serial arterial blood gas monitoring to maintain the pH between 7.45 and 7.55.

TRANSFER TO THE ICU

She was then transferred to the intensive care unit (ICU), where she remained for 2 weeks. While in the ICU, she had a single recurrence of wide-complex tachycardia that resolved immediately with an infusion of 100 mmol of sodium bicarbonate. A urine toxicology screen was negative, and the serum amitriptyline measurement, returned from the laboratory 48 hours after her initial presentation, was 594 ng/mL (reference range 100–250 ng/mL). She was eventually weaned off the norepinephrine infusion after 20 hours, the sodium bicarbonate infusion was discontinued after 4 days, and she was taken off mechanical ventilation after 10 days. Also during her ICU stay, she had seizures on day 3 and developed aspiration pneumonia.

From the ICU, she was transferred to a regular floor, where she stayed for another week and then was transferred to a rehabilitation center. This patient was known to have clinical depression and to have attempted suicide once before. She had recently been under additional psychosocial stresses, which likely prompted this second attempt.

She reportedly had no neurologic or cardiovascular sequelae after her discharge from the hospital.

AMITRIPTYLINE OVERDOSE

Amitriptyline causes a relatively high number of fatal overdoses, at 34 per 1 million prescriptions.¹ Death is usually from hypotension and ventricular arrhythmia caused by blockage of cardiac fast sodium channels leading to disturbances of cardiac conduction such as wide-complex tachycardia.

Other manifestations of amitriptyline overdose include seizures, sedation, and anticholinergic toxicity from variable blockade of gamma-aminobutyric acid receptors, histamine 1 receptors, and alpha receptors.²

In amitriptyline overdose, sinus tachycardia is the most common finding on ECG

Of the various changes on ECG described with amitriptyline overdose, sinus tachycardia is the most common. A QRS duration greater than 100 msec, right to extreme-right axis deviation with negative QRS complexes in leads I and aVL, and an R-wave amplitude greater than 3 mm in lead aVR are indications for sodium bicarbonate infusion, especially in hemodynamically unstable patients.³ Sodium bicarbonate increases the serum concentration of sodium and thereby overcomes the sodium channel blockade. It also alkalinizes the serum, favoring an electrically neutral form of amitriptyline that binds less to receptors and binds more to alpha-1-acid glycoprotein, decreasing the fraction of free drug available for toxicity.⁴

In patients with amitriptyline overdose, wide-complex tachycardia and hypotension refractory to sodium bicarbonate infusion can be treated with lidocaine, magnesium sulfate, direct-current cardioversion, and lipid resuscitation.^5,6 Treatment with class IA, IC, and III antiarrhythmics is contraindicated, as they block sodium channels and thus can worsen conduction disturbances.

A 49-year-old woman with a history of depression, bipolar disorder, and chronic back pain was brought to the emergency department unresponsive after having taken an unknown quantity of amitriptyline tablets.

On arrival, she was comatose, with a score of 3 (the lowest possible score) on the 15-point Glasgow Coma Scale. Her blood pressure was 65/22 mm Hg, heart rate 121 beats per minute, respiratory rate 14 per minute, and oxygen saturation 88% on room air. The rest of the initial physical examination was normal.

She was immediately intubated, put on mechanical ventilation, and given an infusion of a 1-L bolus of normal saline and 50 mmol (1 mmol/kg) of sodium bicarbonate. Norepinephrine infusion was started. Gastric lavage was not done.

Results of initial laboratory testing showed a serum potassium of 2.9 mmol/L (reference range 3.5–5.0) and a serum magnesium of 1.6 mmol/L (1.7–2.6), which were corrected with infusion of 60 mmol of potassium chloride and 2 g of magnesium sulfate. The serum amitriptyline measurement was ordered at the time of her presentation to the emergency department.

Arterial blood gas analysis showed:

• pH 7.15 (normal range 7.35–7.45)
• Paco₂ 66 mm Hg (34–46)
• Pao₂ 229 mm Hg (85–95)
• Bicarbonate 22 mmol/L (22–26).

The initial electrocardiogram (ECG) (Figure 1) showed regular wide-complex tachycardia with no definite right or left bundle branch block morphology, no discernible P waves, a QRS duration of 198 msec, right axis deviation, and no Brugada criteria to suggest ventricular tachycardia.

She remained hypotensive, with regular wide-complex tachycardia on the ECG. She was given an additional 1-L bolus of normal saline and 100 mmol (2 mmol/kg) of sodium bicarbonate, and within 1 minute the wide-complex tachycardia resolved to narrow-complex sinus tachycardia (Figure 2). At this point, an infusion of 150 mmol/L of sodium bicarbonate in dextrose 5% in water was started, with serial ECGs to monitor the QRS duration and serial arterial blood gas monitoring to maintain the pH between 7.45 and 7.55.

TRANSFER TO THE ICU

She was then transferred to the intensive care unit (ICU), where she remained for 2 weeks. While in the ICU, she had a single recurrence of wide-complex tachycardia that resolved immediately with an infusion of 100 mmol of sodium bicarbonate. A urine toxicology screen was negative, and the serum amitriptyline measurement, returned from the laboratory 48 hours after her initial presentation, was 594 ng/mL (reference range 100–250 ng/mL). She was eventually weaned off the norepinephrine infusion after 20 hours, the sodium bicarbonate infusion was discontinued after 4 days, and she was taken off mechanical ventilation after 10 days. Also during her ICU stay, she had seizures on day 3 and developed aspiration pneumonia.

From the ICU, she was transferred to a regular floor, where she stayed for another week and then was transferred to a rehabilitation center. This patient was known to have clinical depression and to have attempted suicide once before. She had recently been under additional psychosocial stresses, which likely prompted this second attempt.

She reportedly had no neurologic or cardiovascular sequelae after her discharge from the hospital.

AMITRIPTYLINE OVERDOSE

Amitriptyline causes a relatively high number of fatal overdoses, at 34 per 1 million prescriptions.¹ Death is usually from hypotension and ventricular arrhythmia caused by blockage of cardiac fast sodium channels leading to disturbances of cardiac conduction such as wide-complex tachycardia.

Other manifestations of amitriptyline overdose include seizures, sedation, and anticholinergic toxicity from variable blockade of gamma-aminobutyric acid receptors, histamine 1 receptors, and alpha receptors.²

In amitriptyline overdose, sinus tachycardia is the most common finding on ECG

Of the various changes on ECG described with amitriptyline overdose, sinus tachycardia is the most common. A QRS duration greater than 100 msec, right to extreme-right axis deviation with negative QRS complexes in leads I and aVL, and an R-wave amplitude greater than 3 mm in lead aVR are indications for sodium bicarbonate infusion, especially in hemodynamically unstable patients.³ Sodium bicarbonate increases the serum concentration of sodium and thereby overcomes the sodium channel blockade. It also alkalinizes the serum, favoring an electrically neutral form of amitriptyline that binds less to receptors and binds more to alpha-1-acid glycoprotein, decreasing the fraction of free drug available for toxicity.⁴

In patients with amitriptyline overdose, wide-complex tachycardia and hypotension refractory to sodium bicarbonate infusion can be treated with lidocaine, magnesium sulfate, direct-current cardioversion, and lipid resuscitation.^5,6 Treatment with class IA, IC, and III antiarrhythmics is contraindicated, as they block sodium channels and thus can worsen conduction disturbances.

A 49-year-old woman with a history of depression, bipolar disorder, and chronic back pain was brought to the emergency department unresponsive after having taken an unknown quantity of amitriptyline tablets.

On arrival, she was comatose, with a score of 3 (the lowest possible score) on the 15-point Glasgow Coma Scale. Her blood pressure was 65/22 mm Hg, heart rate 121 beats per minute, respiratory rate 14 per minute, and oxygen saturation 88% on room air. The rest of the initial physical examination was normal.

She was immediately intubated, put on mechanical ventilation, and given an infusion of a 1-L bolus of normal saline and 50 mmol (1 mmol/kg) of sodium bicarbonate. Norepinephrine infusion was started. Gastric lavage was not done.

Results of initial laboratory testing showed a serum potassium of 2.9 mmol/L (reference range 3.5–5.0) and a serum magnesium of 1.6 mmol/L (1.7–2.6), which were corrected with infusion of 60 mmol of potassium chloride and 2 g of magnesium sulfate. The serum amitriptyline measurement was ordered at the time of her presentation to the emergency department.

Arterial blood gas analysis showed:

• pH 7.15 (normal range 7.35–7.45)
• Paco₂ 66 mm Hg (34–46)
• Pao₂ 229 mm Hg (85–95)
• Bicarbonate 22 mmol/L (22–26).

The initial electrocardiogram (ECG) (Figure 1) showed regular wide-complex tachycardia with no definite right or left bundle branch block morphology, no discernible P waves, a QRS duration of 198 msec, right axis deviation, and no Brugada criteria to suggest ventricular tachycardia.

She remained hypotensive, with regular wide-complex tachycardia on the ECG. She was given an additional 1-L bolus of normal saline and 100 mmol (2 mmol/kg) of sodium bicarbonate, and within 1 minute the wide-complex tachycardia resolved to narrow-complex sinus tachycardia (Figure 2). At this point, an infusion of 150 mmol/L of sodium bicarbonate in dextrose 5% in water was started, with serial ECGs to monitor the QRS duration and serial arterial blood gas monitoring to maintain the pH between 7.45 and 7.55.

TRANSFER TO THE ICU

She was then transferred to the intensive care unit (ICU), where she remained for 2 weeks. While in the ICU, she had a single recurrence of wide-complex tachycardia that resolved immediately with an infusion of 100 mmol of sodium bicarbonate. A urine toxicology screen was negative, and the serum amitriptyline measurement, returned from the laboratory 48 hours after her initial presentation, was 594 ng/mL (reference range 100–250 ng/mL). She was eventually weaned off the norepinephrine infusion after 20 hours, the sodium bicarbonate infusion was discontinued after 4 days, and she was taken off mechanical ventilation after 10 days. Also during her ICU stay, she had seizures on day 3 and developed aspiration pneumonia.

From the ICU, she was transferred to a regular floor, where she stayed for another week and then was transferred to a rehabilitation center. This patient was known to have clinical depression and to have attempted suicide once before. She had recently been under additional psychosocial stresses, which likely prompted this second attempt.

She reportedly had no neurologic or cardiovascular sequelae after her discharge from the hospital.

AMITRIPTYLINE OVERDOSE

Amitriptyline causes a relatively high number of fatal overdoses, at 34 per 1 million prescriptions.¹ Death is usually from hypotension and ventricular arrhythmia caused by blockage of cardiac fast sodium channels leading to disturbances of cardiac conduction such as wide-complex tachycardia.

Other manifestations of amitriptyline overdose include seizures, sedation, and anticholinergic toxicity from variable blockade of gamma-aminobutyric acid receptors, histamine 1 receptors, and alpha receptors.²

In amitriptyline overdose, sinus tachycardia is the most common finding on ECG

Of the various changes on ECG described with amitriptyline overdose, sinus tachycardia is the most common. A QRS duration greater than 100 msec, right to extreme-right axis deviation with negative QRS complexes in leads I and aVL, and an R-wave amplitude greater than 3 mm in lead aVR are indications for sodium bicarbonate infusion, especially in hemodynamically unstable patients.³ Sodium bicarbonate increases the serum concentration of sodium and thereby overcomes the sodium channel blockade. It also alkalinizes the serum, favoring an electrically neutral form of amitriptyline that binds less to receptors and binds more to alpha-1-acid glycoprotein, decreasing the fraction of free drug available for toxicity.⁴

In patients with amitriptyline overdose, wide-complex tachycardia and hypotension refractory to sodium bicarbonate infusion can be treated with lidocaine, magnesium sulfate, direct-current cardioversion, and lipid resuscitation.^5,6 Treatment with class IA, IC, and III antiarrhythmics is contraindicated, as they block sodium channels and thus can worsen conduction disturbances.

The art of medicine includes picking the right drug for the right patient, especially when we can choose between different classes of efficacious therapies. But, in view of our growing understanding of the human genome, can science replace art?

That question is part of the promise of pharmacogenetics, the study of how inter-individual genetic differences influence a patient’s response to a specific drug. A patient’s genome dictates the expression of specific enzymes that metabolize a drug with various efficiencies: variant alleles may result in slightly different proteins that express different enzymatic activity, ie, different substrate affinities for a drug resulting in more or less efficient metabolism. Genomic differences may also dictate whether a specific biochemical pathway is dominant in generating a specific pathophysiologic response, in which case drugs that affect that pathway may be strikingly effective. This may partly explain the various responses to different antihypertensive drugs.

Another less well-understood example of pharmacogenetics is the link between specific HLA haplotypes and a dramatic increase in allergic reactions to specific medications, such as the link between HLA-B*57:01 and abacavir hypersensitivity.

In this issue of the Journal, DiPiero et al discuss thiopurine methyltransferase (TPMT), an enzyme responsible for the degradation of azathioprine, and how knowing the genetically determined relative activity of this enzyme should influence our initial dosing of this and related drugs. Patients with certain variant alleles of TPMT degrade azathioprine more slowly, and these patients are at higher risk of myelosuppressive toxicity from the drug when it is given at the full weight-based dose. The TPMT test is expensive but not prohibitively so, and it would seem that genomic testing is a reasonable clinical and cost-effective option.

As in the abacavir scenario noted above, genomic-based dosing of azathioprine makes scientific sense and offers proof of principle for the validity of pharmacogenomics. But is it truly a clinical game-changer?

The answer depends in part on how the prescribing physician doses the drug, which depends in part on what disease is being treated, how fast the drug needs to be at full dose, and whether there are equally effective alternatives. Recommendations have been offered that state if TPMT activity is normal, we can start at the usual maintenance dose of 1.5 to 2 mg/kg/day (or occasionally more). But if the patient is heterozygous for the wild-type gene and thus is a slower drug metabolizer, then initial dosing “should” be reduced to 25 to 50 mg/day, with close observation of the white blood cell count as the dose is slowly increased to the target. The very rare patient who is homozygous for a non–wild-type allele should not be given the drug.

My usual practice has been to start patients on 50 mg or less daily and slowly titrate up, asking them how they are tolerating the drug and watching the white count—notably, the same approach to be taken if I had done genotyping before starting the drug and had found the patient to be heterozygous for the TPMT gene.

Interestingly, one pragmatic clinical trial tested whether genotyping patients before starting azathioprine—with subsequent suggested dosing of the drug based on the genotype as above—was safer and cheaper than letting physicians dose as they chose.¹ It turned out that physicians participating in this study still dosed their patients conservatively. Even knowing that they might be able to give full doses from the start in patients with normal TPMT activity, many chose not to. I assume that many of those physicians felt as I do that there was no urgency in reaching the presumed-to-be-effective full weight-based therapeutic dose. (We don’t have a good clinical marker of azathioprine’s efficacy). At 4 months, the maintenance dose was about the same in all groups.

We have robust evidence to support the role of pharmacogenetics in informing the dosing of several medications, more than just the ones I have mentioned here. And in the right settings, we should use pharmacogenetic testing to limit toxicity and perhaps enhance efficacy in our drug selection. As the field moves rapidly forward, we will have many opportunities to improve clinical care by using our patients’ genomic information.

But like it or bemoan it, even when we have science in the house, the art of medicine still plays a role in our clinical decisions.

The art of medicine includes picking the right drug for the right patient, especially when we can choose between different classes of efficacious therapies. But, in view of our growing understanding of the human genome, can science replace art?

That question is part of the promise of pharmacogenetics, the study of how inter-individual genetic differences influence a patient’s response to a specific drug. A patient’s genome dictates the expression of specific enzymes that metabolize a drug with various efficiencies: variant alleles may result in slightly different proteins that express different enzymatic activity, ie, different substrate affinities for a drug resulting in more or less efficient metabolism. Genomic differences may also dictate whether a specific biochemical pathway is dominant in generating a specific pathophysiologic response, in which case drugs that affect that pathway may be strikingly effective. This may partly explain the various responses to different antihypertensive drugs.

Another less well-understood example of pharmacogenetics is the link between specific HLA haplotypes and a dramatic increase in allergic reactions to specific medications, such as the link between HLA-B*57:01 and abacavir hypersensitivity.

In this issue of the Journal, DiPiero et al discuss thiopurine methyltransferase (TPMT), an enzyme responsible for the degradation of azathioprine, and how knowing the genetically determined relative activity of this enzyme should influence our initial dosing of this and related drugs. Patients with certain variant alleles of TPMT degrade azathioprine more slowly, and these patients are at higher risk of myelosuppressive toxicity from the drug when it is given at the full weight-based dose. The TPMT test is expensive but not prohibitively so, and it would seem that genomic testing is a reasonable clinical and cost-effective option.

As in the abacavir scenario noted above, genomic-based dosing of azathioprine makes scientific sense and offers proof of principle for the validity of pharmacogenomics. But is it truly a clinical game-changer?

The answer depends in part on how the prescribing physician doses the drug, which depends in part on what disease is being treated, how fast the drug needs to be at full dose, and whether there are equally effective alternatives. Recommendations have been offered that state if TPMT activity is normal, we can start at the usual maintenance dose of 1.5 to 2 mg/kg/day (or occasionally more). But if the patient is heterozygous for the wild-type gene and thus is a slower drug metabolizer, then initial dosing “should” be reduced to 25 to 50 mg/day, with close observation of the white blood cell count as the dose is slowly increased to the target. The very rare patient who is homozygous for a non–wild-type allele should not be given the drug.

My usual practice has been to start patients on 50 mg or less daily and slowly titrate up, asking them how they are tolerating the drug and watching the white count—notably, the same approach to be taken if I had done genotyping before starting the drug and had found the patient to be heterozygous for the TPMT gene.

Interestingly, one pragmatic clinical trial tested whether genotyping patients before starting azathioprine—with subsequent suggested dosing of the drug based on the genotype as above—was safer and cheaper than letting physicians dose as they chose.¹ It turned out that physicians participating in this study still dosed their patients conservatively. Even knowing that they might be able to give full doses from the start in patients with normal TPMT activity, many chose not to. I assume that many of those physicians felt as I do that there was no urgency in reaching the presumed-to-be-effective full weight-based therapeutic dose. (We don’t have a good clinical marker of azathioprine’s efficacy). At 4 months, the maintenance dose was about the same in all groups.

We have robust evidence to support the role of pharmacogenetics in informing the dosing of several medications, more than just the ones I have mentioned here. And in the right settings, we should use pharmacogenetic testing to limit toxicity and perhaps enhance efficacy in our drug selection. As the field moves rapidly forward, we will have many opportunities to improve clinical care by using our patients’ genomic information.

But like it or bemoan it, even when we have science in the house, the art of medicine still plays a role in our clinical decisions.

The art of medicine includes picking the right drug for the right patient, especially when we can choose between different classes of efficacious therapies. But, in view of our growing understanding of the human genome, can science replace art?

That question is part of the promise of pharmacogenetics, the study of how inter-individual genetic differences influence a patient’s response to a specific drug. A patient’s genome dictates the expression of specific enzymes that metabolize a drug with various efficiencies: variant alleles may result in slightly different proteins that express different enzymatic activity, ie, different substrate affinities for a drug resulting in more or less efficient metabolism. Genomic differences may also dictate whether a specific biochemical pathway is dominant in generating a specific pathophysiologic response, in which case drugs that affect that pathway may be strikingly effective. This may partly explain the various responses to different antihypertensive drugs.

Another less well-understood example of pharmacogenetics is the link between specific HLA haplotypes and a dramatic increase in allergic reactions to specific medications, such as the link between HLA-B*57:01 and abacavir hypersensitivity.

In this issue of the Journal, DiPiero et al discuss thiopurine methyltransferase (TPMT), an enzyme responsible for the degradation of azathioprine, and how knowing the genetically determined relative activity of this enzyme should influence our initial dosing of this and related drugs. Patients with certain variant alleles of TPMT degrade azathioprine more slowly, and these patients are at higher risk of myelosuppressive toxicity from the drug when it is given at the full weight-based dose. The TPMT test is expensive but not prohibitively so, and it would seem that genomic testing is a reasonable clinical and cost-effective option.

As in the abacavir scenario noted above, genomic-based dosing of azathioprine makes scientific sense and offers proof of principle for the validity of pharmacogenomics. But is it truly a clinical game-changer?

The answer depends in part on how the prescribing physician doses the drug, which depends in part on what disease is being treated, how fast the drug needs to be at full dose, and whether there are equally effective alternatives. Recommendations have been offered that state if TPMT activity is normal, we can start at the usual maintenance dose of 1.5 to 2 mg/kg/day (or occasionally more). But if the patient is heterozygous for the wild-type gene and thus is a slower drug metabolizer, then initial dosing “should” be reduced to 25 to 50 mg/day, with close observation of the white blood cell count as the dose is slowly increased to the target. The very rare patient who is homozygous for a non–wild-type allele should not be given the drug.

My usual practice has been to start patients on 50 mg or less daily and slowly titrate up, asking them how they are tolerating the drug and watching the white count—notably, the same approach to be taken if I had done genotyping before starting the drug and had found the patient to be heterozygous for the TPMT gene.

Interestingly, one pragmatic clinical trial tested whether genotyping patients before starting azathioprine—with subsequent suggested dosing of the drug based on the genotype as above—was safer and cheaper than letting physicians dose as they chose.¹ It turned out that physicians participating in this study still dosed their patients conservatively. Even knowing that they might be able to give full doses from the start in patients with normal TPMT activity, many chose not to. I assume that many of those physicians felt as I do that there was no urgency in reaching the presumed-to-be-effective full weight-based therapeutic dose. (We don’t have a good clinical marker of azathioprine’s efficacy). At 4 months, the maintenance dose was about the same in all groups.

We have robust evidence to support the role of pharmacogenetics in informing the dosing of several medications, more than just the ones I have mentioned here. And in the right settings, we should use pharmacogenetic testing to limit toxicity and perhaps enhance efficacy in our drug selection. As the field moves rapidly forward, we will have many opportunities to improve clinical care by using our patients’ genomic information.

But like it or bemoan it, even when we have science in the house, the art of medicine still plays a role in our clinical decisions.