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Co-trimoxazole
Used in the Treatment of AIDS
The following are comments from Dr. Stuart Levy
With great concern,
I read the recent report by Donald G. McNeil, Jr., which describes
recommendations by the World Health Organization and the United
Nations AIDS program to provide "regular doses" of the antibiotic
co-trimoxazole for the prevention of bacterial and parasitic diseases
in AIDS patients in Africa.
I understand why
the recommendation has been made, but am considerably worried
by the potential consequence of this action -- the emergence of
resistance to the drug. The Lancet recently reported the appearance
of drug-resistant Pneumocystis carinii and resistance to co-trimoxazole
in E. coli causing urinary tract infections has almost tripled
in frequency in the United States. The widespread use of this
drug to treat prophylactically the 23 million African AIDS patients
will almost certainly increase the frequency of drug resistance
in organisms against which the treatment is directed.
While there is perceived
benefit to the patients in the prevention of disease, the positive
aspects may be short-lived unless measures are included to curb
resistance. Providers should determine how, when, and to what
extent the medication should be prescribed. Any limits to broad-scale
use will curtail resistance selection. Controls on the quantity
and length of time on the drug will help, because resistance to
antibiotics directly correlates with both these parameters. Monitoring
for drug resistance should be instituted so that any emerging
resistance can be recognized, and appropriate measures taken,
before it is too late.
The microbial world
is already primed to confront this antibiotic onslaught. Resistance
genes to both components of this drug combination, sulfamethoxazole
and trimethoprim, are present on genetic elements which can transfer
among different kinds of bacteria. If provided too broadly, without
appropriate guidelines, this effective drug could quickly become
useless against the very diseases for which it is being recommended.
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