Prophylaxis and prophylactics: better together?

For the first time, an advisory committee to the FDA has recommended that the agency approve a drug to prevent the transmission of HIV. The drug Truvada, a combination of two antiretroviral drugs, is not new and has actually been in use to treat HIV since 2004. However, this would be the first pharmaceutical method used in HIV-negative people to reduce an individual s risk of contracting the virus.

Studies have demonstrated that taking Truvada daily can significantly lower a person s risk of contracting HIV, the virus that causes AIDS. One study of almost 2,500 gay men in six countries found that, overall, men prescribed Truvada had a 44 percent lower risk of infection. Yet the efficacy rate is probably much higher: That number included the men who were not consistent in taking the medication. Of those men whose blood tests indicated that they were taking the medication exactly as directed, there was an impressive 90 percent lower risk of contracting HIV.

The advisory committee had to take into account the risks and benefits of using Truvada for HIV prevention when coming to their decision. On the one hand, an individual who is taking Truvada when he becomes infected with HIV may develop drug-resistant forms of the virus. But on the other hand, there are still 50,000 new HIV infections every year in the U.S., and this number has remained steady for the past 15 to 20 years. As many panelists noted, this indicates that the currently available prevention methods, such as condoms and counseling, just aren t working and there is a serious need for a different approach. The panel thus voted that Truvada should be available as a preventive measure for people who are at high risk of HIV infection, including gay men with multiple sex partners, prostitutes, and individuals who are in relationships with an HIV-positive person.

Some have raised concerns that people taking Truvada for HIV prevention might end up having a false sense of security, which could lead them to become less vigilant about safe sex measures. But Gilead, maker of the drug, has stated that, if Truvada is approved for prevention, the company will provide educational materials emphasizing the importance of condom use, counseling, and regular HIV testing even while taking the drug. And as Dr. Robert Grant, one of the research leaders of the Truvada study on gay men, explains, notions that taking Truvada as prophylaxis will result in a decrease of condom use is just as unrealistic as predictions in the 1970 s that car safety airbags would lead to a decrease in seat belt use. That just didn t happen, says Dr. Grant. Like airbags, people would thus think of Truvada as an added level of security that doesn t preclude the need for condoms.

As ACSH s Dr. Elizabeth Whelan explains, It will be essential to make patients aware that this drug does not provide complete protection from HIV. They still need to practice safe sex this is just one added protection.

ACSH s Dr. Josh Bloom believes that the use of medication for HIV prevention will be an important breakthrough. This is really a major turning point in the AIDS epidemic, he says, both medically and ethically. The quest for an AIDS vaccine is three decades old, and still going nowhere fast. I doubt that many scientists would have ever predicted that the first prophylactic agent would be in the form of a pill.