Lighter "Cocktail"
AIDS "Maintenance"
Regimen Likely To Fail
BOSTON (Reuters) - New evidence suggests that people with the AIDS virus who have been successfully treated with a ''cocktail'' of drugs may have to keep taking them indefinitely, according to two studies published in Thursday's New England Journal of Medicine. The studies found that when patients were switched to a ''maintenance'' regimen with fewer drugs, the HIV that causes AIDS began to reestablish itself in their bodies.
The cocktail is a combination of three, four or five different drugs that must be taken on a rigid schedule throughout each day. Doctors have been looking for a way to enable patients to switch to a more convenient regimen of just one or two drugs after HIV has been driven to undetectable levels in their blood. An editorial in the Journal by Dr. David Cooper and Sean Emery of the University of New South Wales in Sydney, Australia, said the results suggested that, ``for the moment, treatment must be seen as a lifelong undertaking'' because the body's immune system is unable to mop up the remnants of the virus. Both studies used three drugs to send the AIDS virus into hiding. The drugs were zidovudine (better known as AZT), sold under the brand name Retrovir by Glaxo Wellcome, lamivudine, another Glaxo product sold under the brand name Epivir, and indinavir, sold under the brand name Crixivan by Merck Sharp and Dohme. In the first study, led by Dr. Diane V. Havlir of the University of California at San Diego, one third of the 316 volunteers remained with the triple-drug treatment, another third switched to indinavir alone, and the rest continued with just AZT and lamivudine. After six months, only four percent of the patients who continued to get all three drugs saw their virus levels increase, compared with 23 percent in the two groups who received the less-intense treatment.
The findings mean that if patients fail to take even one drug in their multi-drug treatment schedule, virus levels may rebound. It ``leaves little margin for error,'' the Havlir team said. The second study, based in France and led by Dr. Gilles Pialoux of the Pasteur Institute in Paris, included 279 adults. Virus levels rose in nine percent of the patients who continued to take all three drugs, 31 percent of the volunteers who were switched to AZT and lamivudine, and 22 percent who got AZT and indinavir. In their editorial, Cooper and Emery said the results still held some reason for hope because the practice of giving fewer drugs was nonetheless effective in the majority of the volunteers. ``Whether such patients are likely to relapse in the longer term is unclear,'' they wrote. It is also possible that patients will do better if doctors keep them on the cocktail longer before scaling back the treatment. Complicating the findings is the issue of AZT resistance. In many patients, the AIDS virus learns to shrug off the drug. Some of the volunteers had been taking AZT before they started receiving the cocktail.
These patients may do poorly with maintenance therapy, Cooper and Emery speculated, because the AIDS virus in their bodies may have already begun to develop a resistance to AZT. Thus, a two-drug combination may, in effect, be a one-drug regimen for them.