Records show that as far back as 1850 B.C.E., women attempted to control their fertility by concocting spermicides (London, 1992). Nonoxynol-9, an FDA-approved spermicide, has been available to women to prevent pregnancy since the 1950s. Today, nonoxynol-9 is the active ingredient in all spermicides in the U.S. Spurred by the AIDS epidemic and by the discovery in the 1980s that nonoxynol-9 can inactivate HIV (the virus that can cause AIDS) in a test tube, researchers have sought to determine whether nonoxynol-9 could also be used as a means of preventing sexually transmitted infections (STIs) (Richardson, 2002). Recently, the World Health Organization (WHO) and Centers for Disease Control and Prevention (CDC) issued recommendations advising against nonoxynol-9 for reducing the risk of infection. This fact sheet reviews the research about the safety, efficacy, and recommended usage of nonoxynol-9.

Nonoxynol-9 and Contraception

Spermicides are an integral component of vaginal barrier birth control methods such as the diaphragm, cervical cap, and sponge, or they can be used alone in the form of foam, creams, jelly, film, or suppositories (Cates & Raymond, 1998). In 1995, 4.6 percent of contracepting American women used these methods of vaginal spermicide — sometimes alone, as a primary method, but mostly in conjunction with another method (WHO/CONRAD, 2002). Nonoxynol-9 is an ingredient that is contained in three types of over-the-counter products — in contraceptive products designed exclusively for vaginal use (foam, creams, jelly, film, and suppositories), in some sexual lubricants, and in some lubricated condoms. It is a chemical that kills sperm by destroying the sperm cell membrane. In some spermicide products, the formulation (foam, cream, jelly, etc.) may also work to prevent pregnancy by acting as a barrier. Most spermicide products on the market have between 52 mg and 150 mg of nonoxynol-9 per dose. Nonoxynol-9 concentration ranges from one percent in some spermicide-coated condoms and lubricants to 28 percent in vaginal contraceptive film (Cates & Raymond, 1998). Nonoxynol-9 use has been shown to cause skin irritation in some women and men, and may increase a woman’s risk of urinary tract infection (Althaus, 1997; Cates & Raymond, 1998).

Contraceptive Efficacy

Because nonoxynol-9 has been on the market for more than half a century, most studies of the effectiveness of spermicides used alone to prevent pregnancy do not meet the standards of contemporary study design and analysis (Cates & Raymond, 1998). The studies that have been done have found a wide range of failure rates for typical use, from less than two percent to 59 percent (WHO/CONRAD, 2002). A study conducted with contemporary methods of design and execution comparing the Vaginal Contraceptive FilmTM with Conceptrol® foaming tablets among 765 women found that with typical use, within six months, 25 percent of the women using the film, and 28 percent of the women using the foaming tablets got pregnant (Raymond & Dominik, 1999). Spermicide seems to boost the efficacy of the diaphragm. A randomized trial found a typical use, 12-month pregnancy rate of 21 percent when a diaphragm was used with spermicide, as compared to 29 percent without spermicide (Bounds, et al., 1995). There is currently no evidence, however, that condoms lubricated with nonoxynol-9 (N-9) are more effective at preventing pregnancy than other lubricated condoms — yet, the World Health Organization advises that “it is better to use N-9 lubricated condoms than no condoms” (WHO/CONRAD, 2002).

Nonoxynol-9 and Sexually Transmitted Infections

In the 1980s, it was discovered that nonoxynol-9 had the ability to inactivate, in vitro, several sexually transmitted infections, including gonorrhea, chlamydia, trichomonas, herpes simplex virus, and HIV (Ricardson, 2002; Roddy, et al., 2002). Subsequent research sought to determine whether nonoxynol-9, used in various formulations, could also be used as a microbicide against these infections. The results of early studies were often conflicting, but overall mildly encouraging — a 1988 study found that the use of nonoxynol-9 gel slightly reduced the risk of women contracting chlamydia and gonorrhea (Louv, et al., 1988; WHO/CONRAD, 2002). Similarly, a 1992 study involving female sex workers in Thailand found a 25 percent reduction in the incidence of cervical infection with nonoxynol-9 film use (Niruthisard, et al., 1992).

More recent studies have shown, however, that nonoxynol-9 does not provide protection against STIs, and that in some cases, it may actually increase the risk of transmission by irritating the epithelium of the vagina and anus (CDC, 2002; WHO/CONRAD, 2002).

• A randomized study of women sex workers found a slightly higher risk of gonorrhea, a slightly lower risk of chlamydia, and no change in risk for HIV among women using film with 70 mg of nonoxynol-9 (Roddy, et al., 1998).

• A subsequent study of women with high STI risk who were not sex workers compared nonoxynol-9 gel and condom use against condom use alone for the prevention of gonorrhea and chlamydia. The women who used the gel had a 20 percent higher incidence of gonorrhea or chlamydia or both than women who only used condoms. Women had a 50 percent greater chance of acquiring gonorrhea if they used the gel than women who did not, but gel users had a comparable probability of acquiring chlamydia (Roddy, et al., 2002).

• One highly publicized randomized, four-year study involving nearly 1,000 sex workers found that the use of a gel with 52.5 mg of nonoxynol-9 increased risk of HIV infection by 50 percent. The women in this study reported very high rates of sexual activity, averaging 75 sexual encounters per month. The women who used the gel most frequently — some women used it up to 20 times a day — were at the greatest risk of infection (Van Damme, 2000).

Nonoxynol-9 as an Irritant

Nonoxynol-9 can irritate the skin of the vulva, vagina, or penis (Cates & Raymond, 1998). It has also been found to cause epithelial disruption — lesions and/or exfoliation of the cellular lining of the vagina and rectum, which may increase the chances of infection. Studies on the safety of nonoxynol-9 products used vaginally varied in the formulations used, the dosages and concentrations, the frequency and duration of use, and other methodologies. Taken together, these studies showed a greater tendency toward epithelial disruption with greater frequency of use and higher doses (WHO/CONRAD, 2002). For example, one study tested the rate of vaginal epithelial disruption among women who used a suppository containing 150 mg of nonoxynol-9. Epithelial disruption was suffered by 15 percent of placebo users, 18 percent of women who used the product every other day, 34 percent who used the product daily, 29 percent who used the product twice per day, and 53 percent who used the product four times per day (Roddy, et al., 1993). It has also been found that nonoxynol-9 may cause greater epithelial disruption of the rectum, resulting in a potential increased risk of infection. For this reason, the CDC and WHO advise that nonoxynol-9 should not be used during anal sex (CDC, 2002; Phillips, et al., 2000; WHO/CONRAD, 2002).

Who Should Use Nonoxynol-9 Products and Under What Conditions?

Based on these findings, the World Health Organization and the Centers for Disease Control and Prevention issued the following directives for the use of nonoxynol-9:

• Nonoxynol-9 is appropriate for contraceptive use in some instances. For women at low risk of HIV infection, the contraceptive use of nonoxynol-9 — foam, creams, jelly, film, and suppositories — alone, or preferably in conjunction with a barrier method, remains an option. However, women who have multiple daily acts of vaginal intercourse should choose another contraceptive method (WHO/CONRAD, 2002).

• Nonoxynol-9 is not a microbicide — it should not be used for protection against sexually transmitted infections. The World Health Organization has concluded that “N-9 should not be used for the purpose of STI or HIV prevention. Condoms should always be used to prevent infection” (WHO/CONRAD, 2002).

• Nonoxynol-9 should not be used for anal sex. The Centers for Disease Control and Prevention advises that “N-9 can damage the cells lining the rectum, thus providing a portal of entry for HIV and other sexually transmissible agents. Therefore, N-9 should not be used as a microbicide or lubricant during anal intercourse” (CDC, 2002).

Now that it has been determined that nonoxynol-9 is not an effective way to reduce the risk of infection, it is imperative that the development of safe, effective microbicides becomes a priority. The development of a microbicide against HIV would have a profound effect on the health of people worldwide. A conservative estimate is that use of microbicides would spare 2.5 million women, men, and children from HIV infection every three years (Microbicide Initiative, 2002). Studies show that many women are very interested in using microbicides — a survey of American women estimated that there are more than 21 million women in the U.S. who are interested in a product specifically for STI risk reduction (Darroch & Frost, 1999).

Until effective microbicides and alternate forms of spermicide are developed, condoms must be widely promoted and distributed to both reduce the risk of unplanned pregnancy and infection. Condoms are an effective, inexpensive form of birth control. Of 100 women whose partners use condoms inconsistently or incorrectly, 14 will become pregnant in the first year of use. Only three will become pregnant if condoms are used consistently and correctly (Warner & Hatcher, 1998). Condoms also offer effective protection against most serious sexually transmitted infections by preventing the exchange of body fluids (Cates & Stone, 1992; CDC, 2002; Stone, et al., 1999). Such fluids — semen, genital discharge, or infectious secretions — are the primary routes of transmission (Stone, et al., 1999). While latex condoms may not completely prevent skin-to-skin contact, they offer the best protection possible for sexually active women and men who want to reduce the risk of infection (Stone, et al., 1999).

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