Single drug performs well in clinical trial

Sunday, August 20, 2006 Doctors are reluctant to stop prescribing the three-drug cocktail. LOS ANGELES TIMES TORONTO — Patients who took a single antiviral drug to combat AIDS fared as well as those on the typical three-drug cocktail, suggesting a simpler and cheaper way of suppressing the virus in the bloodstream, according to several preliminary studies presented Thursday at the International AIDS Conference. Three of the studies involved patients who relied on a cocktail of antiretroviral drugs to get the amount of virus under control before slimming down to a single drug from a class known as protease inhibitors. In a fourth study, one group of patients began their treatment with only a single protease inhibitor. The protease inhibitors were boosted with a compound called ritonavir to increase the drug's lifespan in the bloodstream. A simplified regimen could mean lower drug costs and ease some of the side effects from commonly used combination drugs, such as fat redistribution, anemia and kidney problems. It could also keep more powerful drugs in reserve if a patient stops responding to the first-line therapy, said Dr. Joseph C. Gathe, Jr., a Houston infectious diseases expert who was involved with one of the studies. But many doctors said they were skeptical. If a single drug fails to keep the viral replication under control, the virus could quickly become resistant to it. That fear motivated the development of triple-drug cocktails more than a decade ago. For the future The single-drug therapy "is potentially viable for the future, but I wouldn't use it routinely in practice now," said Dr. Scott Hammer, an infectious diseases specialist at Columbia University Medical Center who led the development of new AIDS treatment guidelines for the International AIDS Society-USA. Some patients cannot tolerate certain kinds of drugs, or don't want to take them. For that small group, doctors might consider the single-drug therapy with the boosted protease inhibitor. Combination therapy, pioneered in the mid-1990s, worked so well for so many years that no one thought to change the regimen, said Dr. Susan Swindells, lead author of a simplification study using a protease inhibitor called atazanavir. The study was published this week in the Journal of the American Medical Association.