Is Emtricitabine-Tenofovir Disoproxil Fumarate Pre-exposure Prophylaxis for the Prevention of Human Immunodeficiency Virus Infection Safer Than Aspirin?

Background.  The safety and effectiveness studies of emtricitabine-tenofovir disoproxil fumarate (FTC-TDF) for human immunodeficiency virus (HIV) infection pre-exposure prophylaxis (PrEP) in men and women showed that daily use reduced the risk of HIV acquisition, but there still may concerns about safety. Methods.  A narrative review was done in September 2015 comparing the 5 major studies on PrEP for HIV infection-Preexposure Prophylaxis Initiative (N = 2499; 3324 person-years), Partners Preexposure Prophylaxis (N = 4747; 7830 person-years), TDF2 (N = 1219; 1563 person-years), Preexposure Prophylaxis Trial for HIV Prevention among African Women (N = 2056; 1407 person-years), and Vaginal and Oral Interventions to Control the Epidemic (N = 4969; 5509 person-years)-and the 2 major studies on aspirin safety-Physicians' Health Study (N = 22 071; over 110 000 person-years) and the Women's Health Study (N = 39 876; approximately 400 000 person-years). The numbers needed to harm (NNH) were calculated for FTC-TDF for HIV infection PrEP and aspirin. Results.  The NNH for FTC-TDF in men who have sex with men and transgender women was 114 for nausea and 96 for unintentional weight loss; in heterosexual couples, the NNH was 68 for moderate decreased absolute neutrophil count. For aspirin, the NNH was 909 for major gastrointestinal bleeding, 123 for any gastrointestinal bleeding, and 15 for any bleeding problems in men. In women, the NNH for easy bruising was 10. Conclusions.  We conclude that FTC-TDF for PrEP for HIV infection favorably compares with aspirin in terms of user safety. Although long-term studies are needed, providers should feel reassured about the safety of short- and medium-term PrEP for HIV infection with FTC-TDF.