Preventing HIV with a Pill

Pre-exposure prophylaxis pill may prevent new human immunodeficiency virus infections

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) A single pill could soon become an important tool in the fight against HIV.

A recent study from the UK found that a medication regimen called pre-exposure prophylaxis (PrEP) may reduce the risk of human immunodeficiency virus (HIV) infection in patients who are at substantial risk of infection. This method is intended to be used in combination with condoms and other HIV prevention methods.

The pill (brand name Truvada) contains two medications (tenofovir and emtricitabine). When a patient is exposed to HIV, these drugs can help keep the virus from establishing a permanent infection.

In an editorial about this study, Kenneth H. Mayer, MD, director of the Brown University AIDS Program, wrote, "The [study] results show that PrEP should be a part of the range of services offered by any clinical program that focuses on sexual health."

A team of researchers led by Sheena McCormack, MSc, an epidemiologist at University College London, tested the pill on 544 gay men who were HIV-negative at the start of the study. All of the men had unprotected sex at least once in the previous 90 days.

About half of these men began taking PrEP immediately. The other half waited for one year before starting treatment.

After one year, three patients in the immediate group were diagnosed with HIV — compared to 20 patients in the other group. This amounts to an 86 percent drop in HIV risk.

Some side effects of the drug included nausea, headache and joint pain.

"HIV prevention services should be expanded worldwide by offering PrEP routinely to those who could benefit," Dr. Mayer said.

The study and editorial were published Sept. 10 in the journal The Lancet.

University College London, Public Health England and Gilead Sciences funded this research. Several study authors disclosed ties to companies that made drugs used in HIV treatment.

Review Date: 
September 9, 2015
Last Updated:
September 18, 2015