Tenofovir Anti-AIDS Gel Shows Early Promise
Preliminary tests of a vaginally applied gel containing tenofovir (also known by the brand name Viread)-an antiviral drug prescribed orally for HIV-positive patients-indicate that the gel has no safety problems. The gel was designed to prevent transmission of the HIV virus, which causes AIDS.
The study by Kenneth H Mayer, MD, an infectious-disease physician at Brown University, and colleagues was published in the February 28 issue of the journal AIDS and reported by HealthDay.com on February 10, 2006.
Search for an Effective Drug
The worldwide spread of AIDS and the fact that no one has yet developed an effective HIV vaccine, the need for an effective way to prevent HIV transmission (other than abstinence or condoms) has become an urgent issue.
Findings of the study by Mayer et al are encouraging. "It's past the first several hurdles, but there are major hurdles to go," said Dr Willard Cates, president of the non-profit Family Health Institute, whose parent organization helped support the new research, according to HealthDay.com.
Researchers are also examining the utility of giving Viread in pill form to men and women not infected with HIV before sexual intercourse, according to HealthDay.com.
The study involved 84 women, aged 18-45 years, from Providence, Rhode Island, Philadelphia and New York City. Twenty-four were infected with HIV.
The women applied tenofovir gel for 14 consecutive days to see if it caused any physical problems. The researchers reported that experienced no serious side effects, although some women had itching and vaginal discharge.
This study was not designed to test whether tenofovir gel works, but only to gauge its safety. Test on the gel's effectiveness remain to be done. However, studies in monkeys suggest that tenofovir gel may prevent infection with simian immunodeficiency virus, a virus similar to AIDS that only infects monkeys.
Tenofovir prevents the AIDS virus from entering cells and then using them to reproduce itself, said study lead author Dr Mayer. The tenofovir gel has been developed wit the ultimate goal that it will get inside cells in the vagina and protect them, just like the oral version of tenofovir.
The next tenofovir gel study will examine its use in women at higher risk of getting HIV, at at the effects of extended use of the drug, Mayer reportedly said. "If the drug gets into the tissue and stays around for a while, maybe you don't have to take it right before you have sex. Maybe you could take it once a day".
However, he cautioned that any new treatment using a tenofovir gel will take at least 3-5 years to eventuate, as testing must still be undertaken to test its effectiveness. "This is the first of many steps," he said.
Anti-AIDS Gel Shows Promise in Early Trials: Vaginal treatment produced few side effects, but much additional testing remains. HealthDay.com, February 10, 2006.
Safety and tolerability of tenofovir vaginal gel in abstinent and sexually active HIV-infected and uninfected women. Kenneth H Mayer et al, AIDS, volume 20(4), pages 543-551, February 28, 2006.
Posted: February 2006
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