Weekly Article: Pre-Exposure Prophylaxix in HIV

by Priya Gopwani

I know this isn't necessarily ED or PEM related, but given the large HIV conference in DC this weekend I thought it was fitting.  The article I actually initially read was in the Washington Post and it discussed the recent FDA approval of Truvada (tenofovir + emtricitabine) for PRE-exposure prophylaxis against HIV.  This is obviously a big change from our typical idea of POST-exposure prophylaxis.  The approval came after 2 large studies showed a decrease in HIV seroconversion rates in patients taking Truvada vs those not taking the anti-retroviral medication. 

The first study (Grant et al) looked at 2500 MSM or transgendered women having sex with men and randomized them to PrEP vs placebo.  The authors found a 40% reduction in the incidence of HIV seroconversion in patients with prophylaxis as compared to those without prophylaxis.  The second study (I had a hard time locating the full text, citation below), looked at partners where one was known HIV +, and looked at both tenofovir alone and Truvada.  They found a 60-75% reduction in HIV seroconversion rates in both men and women with either PrEP method.  Given these encouraging numbers, the FDA approved Truvada for PrEP in high risk individuals (MSM, known + partners, etc).  Further studies have raised some question about the efficacy of Truvada for PrEP in women as compared to men, having to do with the differences in the behavior of the virus and the differences in mucosal membrane characteristics, etc - but we'll leave that for another time!

Obviously there are dangers and downsides to consider.  One is cost, as Truvada is not an inexpensive medicine.  The other is the theory that providing PrEP will encourage more dangerous behaviors with less thought to consequence.  Then again, we all hand out free condoms and encourage seatbelts without necessarily encouraging rampant sex and reckless driving.

Either way, I thought this was an interesting and encouraging step away from HIV treatment to true HIV prevention, especially living in Washington DC where the rates of HIV are considerably higher than most places in the US!

Baeten article: 
Baeten J, Colem C 2011. Antiretroviral pre-exposure prophylaxis for HIV-1 prevention among heterosexual African men and women: The partners PrEP study. In The 6th International AIDS Society Conference on HIV Pathogenesis, Treatment and Prevention. Rome.