Preexposure prophylaxis (PrEP) for human immunodeficiency virus (HIV) infection—administering a daily tablet of a US Food and Drug Administration (FDA)-approved HIV antiretroviral fixed-dose combination of tenofovir disoproxil fumarate and emtricitabine (TDF/FTC) (Truvada; Gilead Sciences, Inc) to high-risk uninfected individuals—has galvanized supporters and opponents.
Data show that PrEP is effective in preventing HIV infections in men who have sex with men (MSM), as well as in heterosexually active men and women.1- 3 In intention-to-treat analyses, these studies showed reductions of infections between 44% and 75%, although compliance with daily therapy did not appear to be high. When investigators restricted the analysis to persons with detectable drug levels, effectiveness rates were over 90%. An open label extension study in follow-up to the iPrEX (Iniciativa Profilaxis Pre-Exposición) trial1 found 100% protection for those who had sustained adherence at the level of 4 or more doses per week.4
Raphael J. Landovitz. Optimizing Delivery of Preexposure Prophylaxis—The Next Frontier. JAMA Intern Med. 2016;176(1):85–86. doi:10.1001/jamainternmed.2015.6530