New, Improved! Now With Less Glycerin!

Version of Viread vaginal anti-HIV gel that's safe for rectal use

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Scientists recently developed an anti-HIV gel designed to be applied to the vagina. Now, a reformulated version of the gel appears to be safe for use in the rectum.

Tenofovir (sold under the brand name Viread®) gel is a welcome development in the fight against HIV/AIDS. It has been shown to reduce the risk of HIV infection through vaginal sex. However, tenofovir gel may not be safe or effective when used on the lining of the rectum, which serves as the first line of defense against HIV.

Due to the composition of tenofovir gel, it can be potentially harmful to the lining of the rectum. The gel can cause the cells of the rectal lining to shrink and release water as the react to the higher levels of sugars and salts in the gel. This weakens the cells of the rectal lining. Once the cells are weakened, the rectal lining is a less effective protection against HIV infection.

In order to develop a safe and effective form of tenofovir gel for rectal use, researchers from CONRAD - an organization that holds the rights to develop the gel - made a new form of the gel with less glycerin, a common ingredient in gel-like products.

Researchers from the Microbicide Trials Network then tested the reformulated gel in laboratory tests. They found that the new gel was three times less likely to cause cells in the rectal lining to purge water. More importantly, they found that the reformulated tenofovir gel was just as effective against HIV as the vaginal version of the gel.

The laboratory results are very encouraging, says principal investigator Charlene Dezzutti, Ph.D., associate professor of obstetrics, gynecology and reproductive sciences at the University of Pittsburgh School of Medicine. The promise of the rectal formulation provide a path for clinical studies. She adds that tests of the new gel on both men and women have already begun.

The CDC estimates that over 56,000 Americans were infected with HIV in 2006. At least 1.1 million people are currently living with HIV.

The research from the Microbicide Trials Network - which was funded by the National Institute of Allergy and Infectious Diseases Division of AIDS and the Eunice Kennedy Shriver National Institute of Child Health and Human Development - was presented at the 18th Conference on Retroviruses and Opportunistic Infections.

Reviewed by: 
Review Date: 
March 3, 2011
Last Updated:
March 4, 2011