HIV PrEP Taken Before, After Sex Effective For MSM

Editorial described finding as important addition to treating and preventing HIV.

Taking preventive medication before and after sex, instead of every day, may actually reduce the risk for men who have sex with men from contracting HIV, according to a study published recently in The New England Journal of Medicine.

An 86% risk reduction was noted among men who had unprotected anal sex with men, according to the multi-center study by Jean-Michel Molina, MD, PhD, and colleagues at the Departments of Infectious Disease at Hôpital Saint-Louis, Assistance Publique–Hôpitaux de Paris, Université de Paris Diderot, Sorbonne Paris Cité.

The double-blind trial, which included 400 gay men and transgender women (whom the study defined as being born male but identifying as female) in France and Canada between Feb. 22, 2012 and Oct. 23, 2014, assigned 199 participants to a median of 15 emtricitabine and tenofovir disoproxil fumarate (Truvada, Gilead) pills per month, and 201 participants to placebo.

Only 2 men in the study group contracted HIV, which the researchers attributed to them taking the medicine improperly, compared with 14 participants in the placebo group.

Dr Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID) and Dr  Hilary Marston, Medical Officer and Policy Adviser for Global Health for NIAID, wrote in a related editorial that this study’s findings “demonstrate the safety and efficacy of ‘on-demand’ pre-exposure prophylaxis (PrEP) for men who have sex with men and transgender women, who are at high risk for HIV infection.” and said that this study is an important addition to the advances in treatment and prevention of HIV that have occurred over the past 20 years.

The TDF-FTC group experienced more adverse gastrointestinal effects , including nausea, vomiting, diarrhea, and abdominal pain. There were also increases in creatinine compared with the placebo group. One participant had to discontinue the study due to a suspected drug interaction with dabigatran, which resulted in the recurrence of deep venous thrombosis.

Dr Molina and colleagues stated that long term toxicity of TDF-FTC is unknown, so this will need to be balanced with preventing HIV-1. “While we wait for an effective vaccine against HIV, the use of such preexposure prophylaxis with TDF-FTC among high-risk men could contribute to a reduced incidence of HIV infection,” the study concluded.


1. Molina JM, Capitant C, Spire B et al. On-demand preexposure prophylaxis in men at high risk for HIV-1 infection. N Engl J Med. 2015; 373:2237-2246.

2. Fauci AS and Marston HD. Ending the HIV–AIDS pandemic — follow the science. N Engl J Med. 2015; 373:2197-2199.