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).