The Food and Drug Administration (FDA) on Monday approved the first drug shown to reduce the risk of HIV infection. The agency approved Truvada for use as a preventable measure for people at high risk of acquiring HIV-1, the most common form of HIV.

Two large clinical trials found that when Truvada is taken once daily and used in combination with safer sex practices the risk of HIV infection is significantly lowered:

• by 42 percent in a study sponsored by the National Institutes of Health (NIH) of about 2,500 HIV-negative gay and bisexual men and transgender women, and
• by 75 percent in a study sponsored by the University of Washington of about 4,800 heterosexual couples in which one partner was HIV positive and the other was not.

Debra Birnkrant, M.D., director of the Division of Antiviral Products at FDA, explains that Truvada works to prevent HIV from establishing itself and multiplying in the body. She notes that while this is a new approved use, Truvada is not a new product. It was approved by FDA in 2004 for use in combination with other medications to treat HIV-infected adults and children over 12 years old.

"In the 80s and early 90s, HIV was viewed as a life-threatening disease; in some parts of the world it still is. Medical advances, along with the availability of close to 30 approved individual HIV drugs, have enabled us to treat it as a chronic disease most of the time," Birnkrant says.

"But it is still better to prevent HIV than to treat a life-long infection of HIV," she says.