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Am Fam Physician. 2016;93(6):520

Clinical Question

Among men who have unprotected anal intercourse, does the combination of tenofovir/emtricitabine (Truvada) taken before and after intercourse reduce the risk of human immunodeficiency virus (HIV) infection?

Bottom Line

Preexposure prophylaxis in high-risk men who have unprotected anal intercourse reduces the likelihood of developing HIV (number needed to treat = 17 per year). Participants averaged 15 pills per month, which costs approximately $700 per month ($8,400 per year). Condoms would be a much more cost-effective way to prevent HIV infection (although condoms were not compared with medications in this study). (Level of Evidence = 1b)


The researchers identified 400 HIV-negative men who had unprotected anal intercourse with at least two men in the previous six months. Those with impaired renal function, hepatitis B virus infection, or hepatitis C virus infection were excluded. The patients were randomized to receive tenofovir/emtricitabine, 300 mg/200 mg, or matching placebo. They were told to take two pills between two and 24 hours before intercourse, and a third and fourth pill at 24 and 48 hours after the first two pills were taken. The median age of participants was 35 years, 92% were white, and 73% were not currently in a relationship. The groups were balanced at the beginning of the study, and analysis was by intention to treat. Patients had regular clinic visits and were followed for a median of 9.3 months. Follow-up was good, with a similar number lost in each group (23 and 26 patients). Adherence was also good, with more than 80% having serologic evidence of having taken the drugs in the previous week. Patients in the intervention group were less likely to develop HIV during the study period than those in the placebo group (2 vs. 14 infections, or 0.91 vs. 6.6 per 100 person-years of follow-up; P = .002, number needed to treat = 17 per year). Gastrointestinal adverse effects were more common in the intervention group (14% vs. 5%; P = .002), but otherwise the medication was safe and well tolerated.

Study design: Randomized controlled trial (double-blinded)

Funding source: Government

Allocation: Concealed

Setting: Population-based

Reference: MolinaJMCapitantCSpireBet alANRS IPERGAY Study GroupOn-demand preexposure prophylaxis in men at high risk for HIV-1 infection. N Engl J Med2015; 373( 23): 2237– 2246.

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