FDA approves Truvada pill for HIV prevention.
"Truvada is to be used for pre-exposure prophylaxis (PrEP) in combination with safer sex practices to prevent sexually-acquired HIV infection in adults at high risk. Truvada is the first drug approved for this indication," it said.
Truvada has been on the US market since 2004 as a treatment for people infected with HIV to be used in combination with other antiretroviral drugs.
An FDA advisory panel in May urged the approval of Truvada for prevention when taken in uninfected people after clinical trials showed Truvada could lower the risk of HIV in gay men by 44 to 73 percent.
The pill has been hailed by some AIDS advocates as a potent new tool against human immunodeficiency virus, but some health care providers are concerned it could encourage risky sex behavior.
A study on Truvada published in 2010 in the New England Journal of Medicine included 2,499 men who were sexually active with other men but were not infected with the virus that causes AIDS.
Participants were selected at random to take a daily dose of Truvada -- a combination of 200 milligrams of emtricitabine and 300 milligrams of tenofovir disoproxil fumarate -- or a placebo.
Those in the study who took the drug regularly had almost 73 percent fewer infections. Across the entire study, including those who had not been as diligent in taking Truvada, there were 44 percent fewer infections than in those who took a placebo.
Experts hailed the results as game-changing and the first demonstration that an already-approved oral drug could decrease the likelihood of HIV infections.