- 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.
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- 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.
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- 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.
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- 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.
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