Nonoxynol-9 Does Not Prevent Gonorrhea, Chlamydia Infections, Study Says
Nonoxynol-9, the "most widely used spermicide worldwide," does not protect against infection with gonorrhea or chlamydia, according to a study published in the March 6 issue of the Journal of the American Medical Association, Reuters reports (Reuters, 3/5). Researchers from Family Health International in Durham, N.C., conducted a randomized trial with 1,251 women in Cameroon to compare the use of nonoxynol-9 in conjunction with condoms to the use of condoms alone in preventing male-to-female transmission of both diseases. None of the women were sex workers, but all of the women were deemed to be at high risk for gonorrhea or chlamydia infections because they had previously tested positive or been treated for symptoms of an STD. The women were asked to participate in the study when they presented with STD symptoms at 10 clinics and 10 pharmacies in Yaounde, Cameroon, between October 1998 and September 2000. They were screened for STDs and treated if necessary and were then asked to return two weeks after they completed treatment for follow-up. If they were free of STDs, they were then allowed to join the study within 30 days. The women were randomly assigned to receive either condoms and nonoxynol-9 gel or condoms alone and had monthly follow-up sessions for six months. During those interviews, the women were asked how many times they had engaged in vaginal intercourse in the seven days prior to the interview and how many times they used condoms alone, nonoxynol-9 alone or both in conjunction. Women given nonoxynol-9 and condoms had an infection rate of 43.6 cases of gonorrhea, chlamydia or both per 100 person-years compared to a rate of 36.6 infections per 100 person-years for women in the condom-only group. In addition, five of the women in the spermicide group and four in the condom-only group became infected with HIV, while three women in each group became pregnant during the course of the study. Researchers concluded that nonoxynol-9, "although safe to use, did not protect against gonorrheal and chlamydial infection" (Roddy et al., JAMA, 3/6).
Reaction
Researchers had hoped that nonoxynol-9, which has been used as a spermicide for 50 years, would prove effective against a variety of STDs because it has been successful against many bacteria, including gonorrhea and chlamydia, in the lab. However, those results have not been supported in this and other human studies. Many observers said that the new study's results indicate that it is "time to move on" and look for other types of vaginal microbicides. In an accompanying commentary, Dr. Barbara Richardson of the University of Washington writes, "Clearly, there remains a need for an inexpensive, effective, female-controlled method for preventing sexually transmitted infections." However,
nonoxynol-9 "clearly is not that product," she concludes (Norton, Reuters Health, 3/6). Dr. Mitchell Creinin, director of family planning and family planning research at the University of Pittsburgh, agreed, saying, "This study mainly supports our continued need to fund the research and development of new microbicides that are effective prevention for the transmission of (STDs) and HIV." Three microbicidal products -- Buffer Gel, PRO 2000 and Carraguard
-- are currently being tested, but it "may be a decade" before any new product comes to market. "Until that time, latex condoms remain the best tool to decrease the risk of (gonorrhea), chlamydia or HIV transmission," Creinin said (Willis, ABCNews.com, 3/6).
