Contraceptive Gel Appears Safer Than Nonoxynol-9 : Cellulose sulfate, an experimental vaginal gel, is reported effective in preventing HIV, pregnancy.

WASHINGTON — Cellulose sulfate, a new vaginal gel that is being developed as both a contraceptive and as a means of preventing human immunodeficiency virus and other sexually transmitted infections, is as effective as nonoxynol-9 in preventing pregnancy, and also appears to be safer, researchers wrote in a poster presented at the annual meeting of the American College of Obstetricians and Gynecologists.

The cumulative probability of pregnancy during “typical” and “perfect” use of cellulose sulfate was 13.9 and 3.9, respectively, in a population of 200 heterosexual, fertile couples who used the gel as their primary method of birth control for 6 months as part of a phase II, noncomparative contraceptive effectiveness trial, wrote Dr. Christine Mauck, of the Contraceptive Research and Development (CONRAD) program at the Eastern Virginia Medical School in Arlington, and associates.

Cellulose sulfate is an antimicrobial that stimulates acrosomal loss, inhibits hyaluronidase, and impedes sperm penetration into cervical mucus. Animal studies in rabbits have demonstrated its contraceptive ability. Cellulose sulfate is active against cell-free and cell-associated HIV-1 because it blocks glycoprotein 120-CD4-coreceptor interaction, thereby inhibiting HIV cell entry. Cellulose sulfate has been studied in multiple safety studies of both HIV-free and HIV-infected men and women in which it has been found to be safe, and is currently being studied in two phase III HIV prevention trials, Dr. Mauck wrote.

In this study, the 200 couples were demographically similar with regard to age (27 years for females; 29 years for males), race, and education. Clinic visits were scheduled at enrollment, after one menstrual cycle, and after 6 months or six menstrual cycles, whichever occurred later. Study participants were also asked to phone the clinic 7–10 days after the onset of the first menstrual period, and at the onset of each menses thereafter throughout the study.

There was a mean of 11.5 coital acts per cycle, and 78% of the study subjects used the cellulose sulfate gel alone, as instructed. The gel was used alone, but incorrectly, in 4% of subjects, with an additional contraceptive method in 5% of subjects; 10% of subjects used another method alone, and 4% had unprotected intercourse, Dr. Mauck and her associates wrote.

At the end of the study, 18 women (9%) were pregnant, and 82 (41%) had not become pregnant. Another 14 women (7%) discontinued the study for gel-related reasons; 66 (33%) stopped for other reasons, 18 (9%) said they never used the gel, and 2 patients (1%) were lost to follow-up.

Nonoxynol-9 (N-9), currently the only vaginal contraceptive gel approved for use in the United States, has been associated with an increased risk of HIV, compared with placebo, when used frequently by women at high risk for HIV, Dr. Mauck commented in an interview. “This is why we need a new contraceptive gel. N-9 was found in a previous trial to be associated with a greater risk of HIV seroconversion when used frequently by women at risk of HIV because it's a surfactant and may cause damage to the vaginal epithelium. [Cellulose sulfate gel] appears to be safer than N-9 and may be safer than sexual lubricants like K-Y and at least as effective as N-9,” she said.

WASHINGTON — Cellulose sulfate, a new vaginal gel that is being developed as both a contraceptive and as a means of preventing human immunodeficiency virus and other sexually transmitted infections, is as effective as nonoxynol-9 in preventing pregnancy, and also appears to be safer, researchers wrote in a poster presented at the annual meeting of the American College of Obstetricians and Gynecologists.

The cumulative probability of pregnancy during “typical” and “perfect” use of cellulose sulfate was 13.9 and 3.9, respectively, in a population of 200 heterosexual, fertile couples who used the gel as their primary method of birth control for 6 months as part of a phase II, noncomparative contraceptive effectiveness trial, wrote Dr. Christine Mauck, of the Contraceptive Research and Development (CONRAD) program at the Eastern Virginia Medical School in Arlington, and associates.

Cellulose sulfate is an antimicrobial that stimulates acrosomal loss, inhibits hyaluronidase, and impedes sperm penetration into cervical mucus. Animal studies in rabbits have demonstrated its contraceptive ability. Cellulose sulfate is active against cell-free and cell-associated HIV-1 because it blocks glycoprotein 120-CD4-coreceptor interaction, thereby inhibiting HIV cell entry. Cellulose sulfate has been studied in multiple safety studies of both HIV-free and HIV-infected men and women in which it has been found to be safe, and is currently being studied in two phase III HIV prevention trials, Dr. Mauck wrote.

In this study, the 200 couples were demographically similar with regard to age (27 years for females; 29 years for males), race, and education. Clinic visits were scheduled at enrollment, after one menstrual cycle, and after 6 months or six menstrual cycles, whichever occurred later. Study participants were also asked to phone the clinic 7–10 days after the onset of the first menstrual period, and at the onset of each menses thereafter throughout the study.

There was a mean of 11.5 coital acts per cycle, and 78% of the study subjects used the cellulose sulfate gel alone, as instructed. The gel was used alone, but incorrectly, in 4% of subjects, with an additional contraceptive method in 5% of subjects; 10% of subjects used another method alone, and 4% had unprotected intercourse, Dr. Mauck and her associates wrote.

At the end of the study, 18 women (9%) were pregnant, and 82 (41%) had not become pregnant. Another 14 women (7%) discontinued the study for gel-related reasons; 66 (33%) stopped for other reasons, 18 (9%) said they never used the gel, and 2 patients (1%) were lost to follow-up.

Nonoxynol-9 (N-9), currently the only vaginal contraceptive gel approved for use in the United States, has been associated with an increased risk of HIV, compared with placebo, when used frequently by women at high risk for HIV, Dr. Mauck commented in an interview. “This is why we need a new contraceptive gel. N-9 was found in a previous trial to be associated with a greater risk of HIV seroconversion when used frequently by women at risk of HIV because it's a surfactant and may cause damage to the vaginal epithelium. [Cellulose sulfate gel] appears to be safer than N-9 and may be safer than sexual lubricants like K-Y and at least as effective as N-9,” she said.

WASHINGTON — Cellulose sulfate, a new vaginal gel that is being developed as both a contraceptive and as a means of preventing human immunodeficiency virus and other sexually transmitted infections, is as effective as nonoxynol-9 in preventing pregnancy, and also appears to be safer, researchers wrote in a poster presented at the annual meeting of the American College of Obstetricians and Gynecologists.

The cumulative probability of pregnancy during “typical” and “perfect” use of cellulose sulfate was 13.9 and 3.9, respectively, in a population of 200 heterosexual, fertile couples who used the gel as their primary method of birth control for 6 months as part of a phase II, noncomparative contraceptive effectiveness trial, wrote Dr. Christine Mauck, of the Contraceptive Research and Development (CONRAD) program at the Eastern Virginia Medical School in Arlington, and associates.

Cellulose sulfate is an antimicrobial that stimulates acrosomal loss, inhibits hyaluronidase, and impedes sperm penetration into cervical mucus. Animal studies in rabbits have demonstrated its contraceptive ability. Cellulose sulfate is active against cell-free and cell-associated HIV-1 because it blocks glycoprotein 120-CD4-coreceptor interaction, thereby inhibiting HIV cell entry. Cellulose sulfate has been studied in multiple safety studies of both HIV-free and HIV-infected men and women in which it has been found to be safe, and is currently being studied in two phase III HIV prevention trials, Dr. Mauck wrote.

In this study, the 200 couples were demographically similar with regard to age (27 years for females; 29 years for males), race, and education. Clinic visits were scheduled at enrollment, after one menstrual cycle, and after 6 months or six menstrual cycles, whichever occurred later. Study participants were also asked to phone the clinic 7–10 days after the onset of the first menstrual period, and at the onset of each menses thereafter throughout the study.

There was a mean of 11.5 coital acts per cycle, and 78% of the study subjects used the cellulose sulfate gel alone, as instructed. The gel was used alone, but incorrectly, in 4% of subjects, with an additional contraceptive method in 5% of subjects; 10% of subjects used another method alone, and 4% had unprotected intercourse, Dr. Mauck and her associates wrote.

At the end of the study, 18 women (9%) were pregnant, and 82 (41%) had not become pregnant. Another 14 women (7%) discontinued the study for gel-related reasons; 66 (33%) stopped for other reasons, 18 (9%) said they never used the gel, and 2 patients (1%) were lost to follow-up.

Nonoxynol-9 (N-9), currently the only vaginal contraceptive gel approved for use in the United States, has been associated with an increased risk of HIV, compared with placebo, when used frequently by women at high risk for HIV, Dr. Mauck commented in an interview. “This is why we need a new contraceptive gel. N-9 was found in a previous trial to be associated with a greater risk of HIV seroconversion when used frequently by women at risk of HIV because it's a surfactant and may cause damage to the vaginal epithelium. [Cellulose sulfate gel] appears to be safer than N-9 and may be safer than sexual lubricants like K-Y and at least as effective as N-9,” she said.