About 1.2 million Americans have human immunodeficiency virus (HIV) and each year about 50,000 adults and adolescents are diagnosed with HIV. On July 16, 2012 the Food and Drug Administration (FDA) approved the use of Truvada (emtricitabine and tenofovir) for the prevention (prohylaxis) of HIV transmission in HIV negative adults at risk for HIV infection from sexual intercourse. This is the first drug approved for this use.

What is Truvada

Truvada is a combination of 200 mg Emtriva (emtricitabine) and 300 mg Viread (tenofovir) which are nucleoside analog HIV-1 reverse transcriptase inhibitors. Truvada has been available for treatment of HIV in combination with other anti-HIV drugs since 2004. The new use for Truvada is pre- exposure prophylaxis (PrEP), in combination with safer sex practices, to reduce the risk of sexually acquired HIV-1 in HIV negative adults at high risk. (HIV-1 is the most common form of HIV). The dose for HIV prevention is one tablet once daily with or without food. This is the same dose used for treating HIV infection. 

For Truvada to be effective in preventing HIV-1 infection the following recommendations should be adopted:

• Truvada should be prescribed as part of a comprehensive prevention strategy.
• The dosing schedule must be followed. Noncompliance leads to failure of Truvada to prevent HIV.
• HIV test must be negative before starting treatment with Truvada for HIV prevention
• HIV screening every 3 months

Who is considered at high risk for HIV infection

• Anyone who has partner(s) known to be HIV-1 infected
• Anyone who engages in sexual activity within a high HIV prevalence area or social network and meets one or more of the following:
• inconsistent or no condom use
• Diagnosis of sexually transmitted infections
• Exchange of sex for commodities (such as money, food, shelter, or drugs) use of illicit drugs or alcohol dependence
• incarceration
• Partner(s) of unknown HIV status with any of the factors listed above

How effective is Truvada for preventing HIV-1 infection

• 2499 HIV negative men or transgender women who have sex with men and high risk behaviors were studied. 48 subjects in the Truvada group contracted HIV compared to 83 subjects who received placebo (dummy pill), a risk reduction of 42%.
• In 4758 partners where one partner has HIV, 13 subjects in the Truvada group compared to 52 subjects in the placebo group developed HIV. The risk reduction was 75%.
• In both studies Truvada was more effective when taken as directed.

What are side effects of Truvada

The most common side effects of Truvada are diarrhea, nausea, fatigue, headache, dizziness, depression, insomnia, abnormal dreams and rash. In addition, lactic acidosis, enlarged liver (hepatomegaly), kidney failure, reduced bone mineral density, flare up of hepatitis B infection, redistribution of body fat, and immune reconstitution syndrome (inflammatory response to infection) also occur. Drug resistant HIV-1 viruses were isolated from some subjects who had undetected HIV before receiving Truvada for HIV prevention. 

References

Truvada FDA prescribing information