Women with HIV may need more antiviral medication when compared to men with HIV. Short for the human immunodeficiency virus, HIV wreaks havoc on the immune system, and over time, results in AIDS, acquired immunodeficiency syndrome.
Researchers from the University of North Carolina at Chapel Hill found that while men with HIV could get by with just two doses per week of the antiviral medication Truvada, women with HIV required daily doses.
"Our data highlight the fact that one dose does not fit all," senior study author Angela Kashuba of the UNC Eshelman School of Pharmacy, said. "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."
Previous studies have shown that Truvada has been more successful at lowering HIV infection rates in men when compared to women. The researchers findings specifically showed that different tissues, including vaginal, rectal and cervical tissues, required different dosages of Truvada in order to be effective in reducing infection rates.
During the study, researchers measured how much DNA material was present in human cells in a test tube, as well as how much Truvada was needed to prevent infection in the cells. Then, researchers gave healthy female volunteers Truvada and examined how much got into cervical, rectal and vaginal tissues and how much DNA material was there. Lastly, they created a mathematical model based on the test tube and human data that predicted drug-to-DNA rations in vaginal, cervical and rectal tissues in order to calculate the amount of drugs needed to prevent HIV from infecting human tissues.
Study results showed that twice as much Truvada is needed to reduce infection in both vaginal and cervical tissues than rectal tissues as fewer components of Truvada get into the two tissue types. There is also more DNA material that the virus can reproduce with found in vaginal and cervical tissues, requiring more of the drug to prevent infection.
"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."
The study was published Thursday (March 4) in the Journal of Infectious Diseases.
