Pre-exposure chemoprophylaxis of HIV infection: quo vadis?

The pre-exposure chemoprophylaxis (now commonly referred to as PrEP) of HIV infection has gained increased momentum, concomitantly with the successful use of combination drug regimens for the treatment of AIDS. A pivotal component in the current drug combination regimens for the treatment of AIDS as well as the ongoing PrEP trials is tenofovir disoproxil fumarate (TDF, Viread®) and its combination with emtricitabine (FTC). The combination of TDF with FTC has been marketed as Truvada®. TDF and TDF/FTC has proven effective, if orally administered daily or intermittently, in the prevention of rectal simian human immunodeficiency virus (SHIV) infection in macaques. Topical tenofovir gel has proven effective in the prevention of HIV infection in women in South Africa. Oral TDF/FTC has proven effective in the prevention of HIV infection in men having sex with men, and recent press releases divulged that oral TDF/FTC is also effective in preventing HIV infection in serodiscordant couples in Botswana, Kenya and Uganda. Other PrEP studies are still ongoing. Available data point to the efficacy and safety of TDF with or without FTC in the prophylaxis of HIV infection (AIDS).