Now that the U.S. Food and Drug Administration has approved the use of the antiretroviral drug combination of tenofovir disoproxil fumarate and emtricitabine (Truvada®) for HIV prevention, its success will depend on user adherence to the daily drug regimen.
Several trials of Truvada as pre-exposure prophylaxis (PrEP) showed it is most effective when adherence is high. Two trials, VOICE and FEM-PrEP, were unable to determine whether Truvada worked, likely because most participants did not take the study pills daily as directed.
One explanation for low adherence to PrEP is that study participants might have thought they were not at risk of HIV infection.
A study from FHI 360’s Preventive Technologies Agreement (PTA) explored this possibility. Our analysis of data from a randomly assigned cohort of 150 participants who received Truvada in the FEM-PrEP trial yielded some intriguing results, presented in a late-breaker poster this week at the International AIDS Society conference (IAS 2013) in Kuala Lumpur, Malaysia.