The U.S. Food and Drug Administration has approved the antiretroviral drug Truvada, to be used as a preexposure preventive measure by people who, uninfected, may be exposed to the virus through HIV-positive partners. The drug previously was approved to treat people living with HIV. As a preventive measure the drug would be taken daily, by people who were confirmed to be HIV-negative, and who would be tested for the virus every three months. The FDA approved the use following two placebo-controlled clinical trials, the iPrEx trial, among 2,499 HIV-negative men or transgender women who have sex with men, and the Partners PrEP trial, among 4,758 heterosexual couples in which one partner was HIV-positive and the other was not. The iPrEx trial showed a 42 percent reduction of HIV acquisition risk among those taking Truvada, and the Partners PrEP trial showed a 75 percent risk reduction.While side effects from the drug that included diarrhea, nausea, abdominal pain, headache, and weight loss were reported in the trials, no new side effects were reported.
Gilead Sciences, the company that makes Truvada, is required to collect information that might indicate drug resistance among those who do become infected with HIV while taking the drug for preventive purposes. Gilead also must collect data on outcomes for women who become pregnant while taking the drug.