To avoid the transmission of the HIV virus in penetrative sex, routine use of a condom is the most effective means of prevention. Treatment of the partner already infected helps reduce the risk of transmission.

The use of the combination emtricitabine + tenofovir has been licensed in the USA to prevent transmission in adults considered high-risk, in addition to other measures.

The clinical evaluation of the emtricitabine + tenofovir combination in this situation is based on trials that have shown a risk reduction of around 50% in situations where the risk is very high (those resulting in around 2 to 4 infections per 100 adults per year), with around 1 to 2 fewer infections per 100 adults treated for one year.

These antiretroviral drugs have a shared adverse effects profile, including gastrointestinal disorders (diarrhoea, nausea and vomiting, anorexia), pancreatitis and hepatitis.

Emtricitabine exposes patients to hyperpigmentation of the skin, pruritus, abnormal dreams, insomnia, asthenia, giddiness. Tenofovir sometimes causes kidney failure.

In western Europe, the levels of risk of HIV infection are rarely as high as in the trials carried out with Truvada° (emtricitabine + tenofovir). Some people however expose themselves to a high risk, e.g. within a couple where one partner is HIV positive or through risky sexual behaviour without using a condom. This justifies pursuing the long-term evaluation of this drug as a preventive.

In practice, optimal use of the condom is a more effective means of preventing the sexual transmission of HIV. 

©Prescrire 1 July 2013

"Emtricitabine + tenofovir to prevent HIV transmission" Prescrire Int 2013; 22 (140): 178-181. (Pdf, subscribers only).