August 9, 2012
The CDC issued its second "Interim Guidance" on the use of tenofovir/FTC as pre-exposure prophylaxis for prevention of HIV, this time for prevention of HIV in heterosexually active adults. The rationale?
Since January 2011, data from studies of PrEP among heterosexual men and women have become available, and on July 16, 2012, the Food and Drug Administration (FDA) approved a label indication [for TDF/FTC] for reduction of risk for sexual acquisition of HIV infection among adults, including both heterosexuals and MSM. This interim guidance includes consideration of the new information and addresses pregnancy and safety issues for heterosexually active adults at very high risk for sexual HIV acquisition that were not discussed in the previous interim guidance for the use of PrEP in MSM.
I added the emphasis to the above last sentence, as it's critical that clinicians realize that PrEP with tenofovir/FTC would not be an appropriate preventive intervention for the vast majority of sexually active heterosexual adults in the United States, in whom "community risk" of HIV acquisition is exceedingly low.
That much is pretty clear.
But one area of controversy that has already arisen in clinical practice is whether PrEP is appropriate for serodiscordant couples in whom the infected individual is already on suppressive antiretroviral therapy. It's an unanswered question -- if the risk of transmission is extremely low in these couples but not zero, should PrEP still be considered?
Aside from these small studies (here and here) of its use as part of conception strategy for HIV negative woman who desire pregnancy, we have little if any available data about whether PrEP is worthwhile in this context. The guidance does say, "PrEP use may be one of several options to help protect the HIV-negative partner in discordant couples during attempts to conceive."
But what about the far more common scenario, outside of conception?
Paul Sax is Clinical Director of Infectious Diseases at Brigham and Women's Hospital. His blog HIV and ID Observations is part of Journal Watch, where he is Editor-in-Chief of Journal Watch AIDS Clinical Care.