Rectal use of nonoxynol-9 (N-9) in lubricant or pre-lubed condoms may pose even more risk than previously feared, according to a study by David Phillips, PhD, and his colleagues at the Population Council in New York City. Phillips recruited four volunteers (three men and one woman), injecting them rectally with 50 or 100 mg of N-9-containing lubricant -- the former measurement typically found in one-time-use lube tubes and packets. His team compared the application of two N-9 over-the-counter products, K-Y Plus and ForPlay, to placebos.

Phillips was amazed at the results: N-9-containing lubes had stripped away much of the protective rectal lining in all four people -- a skinning that took hours to heal -- while the lining remained intact with placebos. Phillips is launching a wider study, but based on his findings, he says, “I wouldn’t advise anyone to use N-9 when having rectal sex.”

Phillips’ study deals a mean blow in the decade-long debate over whether N-9, an FDA-approved spermicide, can safely be used to prevent HIV transmission. While the bio-detergent kills HIV, it can also attack the vaginal and rectal membranes, causing lesions that scientists say may serve as entry points for the virus. Last year, N-9 was on the ropes after a large-scale study of Advantage-S, an N-9-based vaginal microbicide product, backfired. The study was intended to test whether women could use the N-9 product, with or without condoms, to prevent HIV. But preliminary data showed that the chemical caused lesions -- and 50 percent more HIV infections -- among the female sex workers who used the product than among those who used a placebo.

Based on these striking stats, last August the Centers for Disease Control and Prevention (CDC) sent a warning to AIDS service providers, declaring that the case stacked against N-9 is “conclusive and significant.” In the letter, the CDC issued interim recommendations against using N-9, regardless of dosage or product: “The possibility of risk, with no benefit, indicates that N-9 should not be recommended as an effective means of HIV prevention.” The CDC reserved its sternest words for rectal use of N-9 and stand-alone vaginal use. The letter also warned against N-9 condoms, saying, “Condoms without N-9 may be a better option.”

The agency’s alert caused AIDS service organizations to turn a collective cold shoulder to N-9 condoms and lubes. “It’s a rare day that we see N-9 products on an AIDS prevention organization’s order,” says Todd Haskell of California-based Total Access, a leading condom distributor. According to Haskell, 90 percent of his AIDS organization customers stopped buying N-9 products as a direct result of the CDC letter. Haskell said that the organizations are instead opting for plain condoms and non-N-9-containing water-based lube. David Mayer of Mayer Labs, the maker of Kimono condoms, reported that from 1999 to 2000, unit sales of N-9 products dropped nearly 50 percent among his public sector customers with many buying plain products instead. Also, California-based Trigg Laboratories recently ceased making the N-9 version of its Wet lubricant -- its flagship product -- after the CDC announcement.

While N-9 is taking a beating in the U.S., more safety information about it could emerge from an upcoming international conference in Geneva, Switzerland. Planned by the World Health Organization and the U.S.-based Contraceptive Research and Development Program, the meeting will focus on the Advantage-S data to determine if the preliminary results might have stemmed partly from the high incidence of sex and resulting frequency of N-9 usage among the sex workers in the study. The group will then undertake the Herculean task of making its own recommendations about the safety and effectiveness of a range of nonoxynol-9-containing products -- from contraceptives to condoms. But for now, using a plain condom with a water-based lube may be the safest bet for HIVers.

9 Reasons to Nix N-9

1. Strips the rectal lining, actually raising risk of HIV transmission.

2. Causes vaginal lesions.

3. Has never been FDA-approved for use against HIV infection.

4. Gets thumbs-down from the CDC for protection against HIV.

5. Many AIDS service providers have stopped ordering condoms and lube.

6. Is dose-dependent -- its risk rises with the frequency and amount used.

7. Can be damaging to women even if no vaginal irritation is felt.

8. Researchers at Family Health International doubt its efficacy.

9. N-9 condoms are less effective than a plain condom slathered with water-based lube.