A phase I comparative study of contraceptive vaginal films containing benzalkonium chloride and nonoxynol-9. Postcoital testing and colposcopy

Benzalkonium chloride (BZK) has been shown in in vitro and in vivo studies to immobilize sperm, to be active against STD-causing organisms, and to penetrate and thicken cervical mucus. A US clinical study of a sponge containing 60 mg BZK showed life table pregnancy rates at 6 and 12 months of 11.7 and 18.9 per 100 women, respectively. BZK is not currently marketed in the US as a contraceptive. The present study aimed to assess 1) the ability of a new contraceptive vaginal film containing either of two doses of BZK to prevent the penetration of sperm into midcycle cervical mucus; 2) the effect of the film on the vaginal epithelium; and 3) the acceptability of the film. All results were compared with VCF, a currently marketed film containing nonoxynol-9 (N-9). Ten women underwent two baseline cycles of postcoital testing in which no film was used, followed by three test cycles in which Allendale-BZK film, a new film containing either 19 or 25 mg BZK, or VCF, containing 70 mg N-9, was used. The sequence of testing cycles was randomized. In each cycle, condoms were used prior to midcycle, then a midcycle cervical mucus specimen was examined to ensure midcycle characteristics and the absence of sperm. Each woman then had intercourse using either no film (baseline cycles) or a test film (test cycles) and returned 2-3 h afterwards. Cervical mucus was again assessed for adequacy and the presence of sperm. Each woman also underwent colposcopy, using a protocol developed by the World Health Organization. The average number of progressively motile sperm seen per high power field was as follows: first baseline cycle, 22.2; second baseline cycle, 22.1; test cycle with film containing 19 mg BZK, 0.2; test cycle with film containing 25 mg BZK, 0.0; and test cycle with VCF containing 70 mg N-9, 0.0. There was no significant difference between baseline cycles or among test cycles in the average number of progressively motile sperm seen (p = 0.78 and p > or = 0.75, respectively). The average number of progressively motile sperm seen in each test cycle did, however, differ significantly from the average number seen in either baseline cycle (p < 0.01). Colposcopy showed superficial de-epithelialization without underlying inflammation in 15-20% of baseline cycles, regardless of whether colposcopy was done before or after coitus; in 50% of cycles in which either dose of BZK was used; and in 69% of cycles in which VCF was used. In all cases women were asymptomatic. Erythema and petechiae were also seen on colposcopy although at a lower frequency than de-epithelialization. There was no difference in the acceptability of the films. A vaginal contraceptive containing either 19 or 25 mg BZK in a new film base appears to be comparable with VCF in preventing sperm from entering midcycle cervical mucus and may be somewhat less disruptive to the vaginal epithelium.

Data complement anti-STD activity of PRO 2000 gel. Contraceptives

Procept, Cambridge, Massachusetts, announced preclinical results demonstrating the contraceptive efficacy of its PRO 2000 topical microbicide gel. In a program of late-breaking discoveries presented at the National Conference on Women and HIV, held in Pasadena, California, Procept scientists described the results of studies recently conducted with PRO 2000. The in vitro results showed that PRO 2000 was contraceptive when rabbits were dosed intravaginally with a gel containing a 4% concentration of PRO 2000. At a concentration about 10 times lower, PRO 2000 did not appear to affect the rabbit pregnancy rate. Results of preclinical tests have indicated that both concentrations prevent HIV infection, suggesting that contraceptive and noncontraceptive formulations of this drug may be developed. "The potential of this compound as an advancement in the area of women's health is significant," said Stanley C. Erck, Procept. "We believe that the contraceptive properties demonstrated by PRO 2000 Gel will complement the anti-HIV/STD activity we will be evaluating in clinical trials." "More than 70% of all HIV infections worldwide follow heterosexual intercourse. A major problem confounding efforts to prevent AIDS in women has been the lack of effective, female-controlled barrier methods. PRO 2000 Gel has been identified as a topical microbicide well suited for use by women to prevent HIV infection. In laboratory studies, PRO 2000 blocked infection by a wide variety of HIV strains and also was active against herpes simplex virus." Clinical studies currently are underway to assess the safety of PRO 2000 Gel in healthy female volunteers. Assuming the results of these studies are positive, additional studies will be conducted to demonstrate safety and efficacy in populations at high risk for HIV infection.

Contraceptive options for the 1990s

Estrogen-progestin combination oral contraceptives (COCs) are well tolerated, offer high reliability, convenience, and ready availability, but require strict adherence to dosing guidelines. Progesterones work by inhibiting ovulation, thickening cervical mucus, and/or suppressing endometrial growth. An FDA advisory committee has concluded that the benefits outweigh the risks of the mifepristone/misoprostol regimen for use in the United States. IUDs are a good choice for women who want to avoid the inconvenience of barrier methods and who cannot use other forms of contraception. Barrier contraceptives offer low cost and easy availability, but lower effectiveness than other methods.

Spermicide effects questioned by FDA panel

Spermicides clearly work better than no contraceptive at all, but there's no way to say how effective they are or whether women should opt for a gel, foam, suppository, or film, a scientific panel concluded. The advisors to the US Food and Drug Administration (FDA) heard disturbing evidence that women who rely on spermicides as their sole contraceptive have anywhere from a 9% to a 57% chance of becoming pregnant within a year. Spermicides appear to work best when used just 30 minutes before intercourse, said Dr. James Trussell of Princeton University. Nobody knows for sure how well spermicides work, and which work best, because the only studies ever performed were flawed. The manufacturers never proved how well their products work because they hit the market in 1950, before the FDA required such proof. The US National Institutes of Health (NIH) plans to begin a study comparing one brand of each type of commercially available spermicide to see how effective they are. The results will not be available for at least 4 years, so the FDA is debating what to tell consumers in the meantime and if that study will be enough. The FDA may soon change spermicide labels at least to rank the products as less effective than other contraceptives, Dr. Lisa Rarick, FDA reproductive health chief, said. Spermicides also should bear a warning that they may cause vaginal irritation, a condition one study suggests might increase a woman's chances of catching HIV, the scientific panel told the FDA. The same panel agreed, however, that spermicides can help protect women against two other sexually transmitted diseases, gonorrhea and chlamydia.

Advantage 24 nonoxynol-9 product discussed at meeting. Contraception (spermicides)

Columbia Laboratories, Inc., Miami, Florida, reported safety data on the spermicidal product Advantage 24 that show it is safe even when administered four times a day, according to data from the UN Global Program on HIV/AIDS (UNAIDS) and the US National Institutes of Health (NIH). The data were reported at a meeting of the Nonprescription Drugs, Reproductive Health Drugs, Anti-Infective Drugs, and Antiviral Drugs advisory committees of the US Food and Drug Administration. Because of its favorable safety profile, Advantage 24 was the only product that UNAIDS selected for testing to determine its effectiveness against the spread of sexually transmitted diseases (STDs). Therefore, in May 1996, Columbia Laboratories and UNAIDS announced the initiation of an international Phase III clinical study of Advantage 24 for the prevention of the heterosexual transmission of HIV and STDs in approximately 2000 women. Additionally, the NIH is performing similar testing in Africa. Advantage 24, which uses Columbia Laboratories' patented bioadhesive delivery system to deliver nonoxynol-9, currently is marketed in the US by Lake Pharmaceuticals, Inc., and in Canada by Roberts Pharmaceuticals, as a long-lasting, vaginally delivered spermicide, pursuant to strategic alliance agreements with Columbia Laboratories.

Association between use of spermicide-coated condoms and Escherichia coli urinary tract infection in young women

Diaphragm/spermicide use increases the risk of urinary tract infection (UTI). To determine whether spermicide-coated condoms are also associated with an increased risk of UTI, the authors conducted a case-control study at a large health maintenance organization in Seattle, Washington. Cases were sexually active young women with acute UTI caused by Escherichia coli, identified from computerized laboratory files during 1990-1993. Age-matched controls were randomly selected from the enrollment files of the plan. Of 1,904 eligible women, 604 cases and 629 controls (65%) were interviewed. During the previous year, 40% of the cases and 31% of the controls had been exposed to any type of condom. The unadjusted odds ratio for UTI increased with frequency of condom exposure from 0.91 (95% confidence interval (CI) 0.65-1.28) for weekly or less during the previous month to 2.11 (95% CI 1.37-3.26) for more than once weekly. Exposure to spermicide-coated condoms conferred a higher risk of UTI, with odds ratios ranging from 1.09 (95% CI 0.58-2.05) for use weekly or less to 3.05 (95% CI 1.47-6.35) for use more than once weekly. In multivariate analyses, intercourse frequency (odds ratio (OR) = 1.14 per weekly episode), history of UTI (OR = 2.64), and frequency of spermicide-coated condom exposure (OR = 3.34 for more than once weekly and 5.65 for use more than twice weekly) were independent predictors of UTI. Spermicide-coated condoms were responsible for 42% of the UTIs among women who were exposed to these products.

Assessment of the anti-microbial agent C31G as a spermicide: comparison with nonoxynol-9

The broad-spectrum anti-microbial agent, C31G, containing an equimolar mixture of n-dodecyl-dimethylamine-N-oxide (C12-N-O) and N-(n-dodecyl), N-dimethyl-glycine (C12-betaine), was tested for spermicidal activity in comparison with the currently used spermicide, nonoxynol-9 (N-9). The rate of sperm cell permeabilization by the spermicides, as assayed with the fluorescent probe, TO-PRO-1, increased as the cube of the C31G concentration, while the rate increase was linear with N-9 concentration. At 0.04%, the rate of sperm cell permeabilization with both spermicides is at the limit of rapid measurement. C31G diffuses through cervical mucus at a more rapid rate than does N-9. C31G has long been known to aid wound healing and reduce inflammation, whereas N-9 has been reported to induce vaginal irritation. C31G would, thus, seem to have the spermicidal efficacy, the broad range of anti-microbial activity, and the lack of inflammatory activity that is sought in the ideal vaginal spermicide.

The diaphragm with and without spermicide. A randomized, comparative efficacy trial

OBJECTIVE

To determine the relative contraceptive efficacy of a diaphragm used with spermicide as compared to one used without.

STUDY DESIGN

Two hundred sixteen women entered the study between September 1985 and December 1990. Of these, 84 were randomly assigned to the diaphragm-only group and 80 to the diaphragm-with-spermicide group as their primary method of contraception. In addition, a spermicide-only group was planned originally to serve as a control group to assess the contribution to efficacy made by a spermicide alone. Thirty-nine women were randomly assigned to this group, and 13 selected themselves for it. All were followed for a maximum of 12 months. The primary outcome variable was accidental pregnancy. The statistical difference between the two diaphragm groups was analyzed.

RESULTS

The 12-month "typical use" failure rates for the diaphragm-only group were 28.6 per 100 women and for the diaphragm-with-spermicide group, 21.2. The 12-month cumulative consistent-use failure rates were 19.3 per 100 women for the diaphragm-only group as compared to 12.3 per 100 women for users of a diaphragm with spermicide.

CONCLUSION

Although the consistent use rates were not significantly different, this study had low statistical power and hence gives no support to the hypothesis that adjunctive spermicide use fails to improve the effectiveness of the diaphragm method, especially in view of the magnitude and direction of the difference observed. Unless a study with sufficient power proves that the use of a diaphragm alone is statistically as effective as use of a diaphragm with spermicide, use of a spermicide in conjunction with the diaphragm continues to be the appropriate clinical recommendation.

Lea's Shield: a phase I postcoital study of a new contraceptive barrier device

Lea's Shield is a new vaginal barrier contraceptive that may offer advantages over existing methods. It is made of silicone which is resistant to petroleum-based lubricants, does not absorb odors, and does not cause allergic reactions in users with latex sensitivity. It has an anterior loop for ease of insertion and removal and a one-way flutter valve. Its novel design has sufficient volume to fill the posterior fornix, which helps keep it in place and prevent sperm from entering the cervical os. This study evaluated with a standard postcoital test (PCT) the ability of the Lea's Shield used with spermicide or non-spermicidal lubricant to prevent sperm from entering midcycle cervical mucus. Ten sterilized women underwent four PCT cycles: one cycle in which no contraceptive barrier was used (a baseline cycle) and 3 cycles in which one of the following was used: Lea's Shield with spermicide, or with non-spermicidal lubricant, or the contraceptive diaphragm used with spermicide. All volunteers demonstrated more than 5 progressively motile sperm per high power field in the cervical mucus after intercourse in the baseline cycle. No motile sperm were found in the cervical mucus in any cycle in which Lea's Shield or the diaphragm was used with spermicide. No motile sperm were found in cervical mucus in 9 of 10 cycles in which Lea's Shield was used without spermicide. Only two progressively motile sperm were present in the cervical mucus of one volunteer who used the shield with non-spermicidal lubricant.(ABSTRACT TRUNCATED AT 250 WORDS)

Lack of evidence for transmission of human immunodeficiency virus through vaginal intercourse

Research in determining risks for human immunodeficiency virus (HIV) transmission is confounded by many issues. They include lack of clarity or specificity in terminology used, respondents misunderstanding of questions, and lying. The base rate of lying (or social desirability responding) by itself is sufficient to account for the small percentage of Americans and Europeans claiming "heterosexual" transmission from partners not known to be intravenous drug users. This study integrates the physiological and epidemiological data on risk factors for HIV transmission with the psychological literature on the frequency of anal intercourse and of lying (in this case to researchers and clinicians about risk factors). When these factors are considered, intravenous and anal activities remain the only clear vectors for HIV transmission. Research suggesting that spermicidals are more effective at inactivating HIV than condoms are at physically containing HIV is also noted.