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Today the National Institutes of Health (NIH) announced results of the international iPrEx trial examining whether drugs used to treat HIV can also help prevent HIV infection. This approach is called pre-exposure prophylaxis, or PrEP. Result of the study showed that a once-daily pill containing tenofovir plus emtricitabine (brand name Truvada®) was safe and provided an average of 44 percent additional protection against HIV infection to men who have sex with men (MSM) and transgendered women who have sex with men, who also received a comprehensive package of prevention services. These services included use of condoms, monthly HIV testing, counseling, and management of other sexually transmitted infections. The level of protection shown varied widely depending on how consistently participants used PrEP. Among those whose took their daily dose on 90% of days, HIV risk was reduced by roughly 73 percent. Among those who missed more than 10% of their doses, HIV risk was reduced by only about 21 percent. These findings suggest an important new tool in the fight against the global HIV epidemic. They also highlight the importance of psychological and behavioral science research in helping reduce HIV risk behaviors and medication adherence.
The CDC has prepared a fact sheet to help people understand the results of this study and their implications. Among the things the CDC thinks anyone considering using or prescribing PrEp should know are:
1) To date, PrEP has only been proven to reduce HIV infection among men who have sex with men, and there are no data regarding its benefit among heterosexuals or injection drug users.
2) Truvada taken once daily is the only regimen proven safe and effective for PrEP, and therefore Truvada is the only medication that should be prescribed for PrEP. Providers and patients should be aware that HIV prevention is not a labeled indication for use of the medication.
3) PrEP should only be used among individuals who have been confirmed to be HIV-negative.
4) PrEP should never be seen as the first line of defense against HIV. It was only proven to be partially effective when used in combination with regular HIV testing, condoms, and other proven prevention methods, and it does not protect against other sexually transmitted infections. Men who have sex with men should still use condoms consistently and correctly and avoid unprotected sex. It is also important to get tested to know their status and that of their partner(s) for certain. Find a place to get free or low cost HIV testing here: http://www.impactprogram.org/?p=202
5) Taking PrEP daily is critical. This study found that PrEP provided a high level of protection only to those who took the pills regularly; protection was very low among those who did not adhere to the daily regimen well.
6) PrEP must be obtained and used in close collaboration with health care providers to ensure regular HIV testing, risk reduction and adherence counseling, and careful safety monitoring.
Dr. Mustanski is the Director of the IMPACT LGBT Health and Development Program at the University of Illinois at Chicago. You can follow the Sexual Continuum blog by becoming a fan on Facebook.
