HIV-Positive Women Need More Frequent Doses of Truvada Than Men

Efficacy of Truvada varies by gender in HIV treatment.

Researchers have discovered that in order to prevent HIV infection, women need to take more frequent disease of an antiviral medication than men.

Truvada is the only FDA-approved prophylactic drug used to help prevent the spread of HIV. The drug has also shown a reduction in HIV rates.

In prior studies that analyzed similar drug adherence rates in Truvada, it was found the drug had a greater effect on reducing infection in men than women.

“Our data highlight the fact that 1 dose does not fit all,” said senior study author, Angela Kashuba, PharmaD. “In determining how best to use drugs to protect people from HIV, we need to understand where in their body they are at risk for being infected, along with the concentration of drug that is needed to protect that site from infection.”

The study, published in the Journal of Infectious Diseases, showed that vaginal, cervical, and rectal tissue had different responses to Truvada.

In fact, twice as much of the drug was needed to prevent HIV infection in cervical and vaginal tissue compared with rectal tissue. This is due to fewer components in Truvada that are able to make it to these tissues, and more DNA material is used by the virus to reproduce in the cervical and vaginal tissues.

“The more DNA material there is available for HIV to work with, the more medicine is needed to block the process,” said lead study author Mackenzie Cottrell, MS, PharmD. “In essence, we calculated the most effective drug-to-DNA ratio for each tissue type.”

During the study, researchers put human cells in a test tube in order to measure how much DNA material was in the cells and how much Truvada was needed for HIV prevention.

Healthy female participants administered Truvada were measured on how much of the drug was able to get into the vaginal, cervical, and rectal tissue, and how much DNA was there.

Researchers were able to create a mathematical model that could predict the drug-to-DNA ratios in the 3 types of tissues and calculate the necessary amount of drugs needed to prevent HIV infection.

The results showed women may need a daily dose of Truvada compared with men, who need to take the drug bi-weekly.

“We are excited to be able to apply our research methods to explain the conundrum of mixed clinical trial results of Truvada prevention, and how men and women should best use HIV prevention therapy,” Kashuba said. “Yet we would like to remind people who are taking pre-exposure prophylaxis that Truvada should be taken every day to reduce the risk of acquiring HIV infection. Patients should not change their medication regimen without first consulting their physicians.”