Her comments echoed the concerns of President Thabo Mbeki, who
last month requested a safety review
of the drug, which has been approved
for use by the Food and Drug Administration in the United States and by
the World Health Organization.
"There exists a large volume of
scientific literature alleging that,
among other things, the toxicity of
this drug is such that it is in fact a
danger to health," Mbeki said in
a speech to provincial leaders.
"These are matters of great concern
to the government as it would be
irresponsible for us not to heed the
dire warnings which medical researchers have been making."
The statements have touched off a
flurry of protests from doctors and
others concerned about AIDS in this
country, which has one of the world's
highest rates of infection with H.I.V.,
the virus that causes the disease.
AIDS experts say concerns about
AZT, particularly for children, have
been raised in the United States. One
study found that pregnant mice
treated with AZT gave birth to babies with tumors. The relevance for
humans is unknown.
But after reviewing the mouse
studies and others like it, the National Institutes of Health determined in
1997 that the benefits of the drug far
outweigh the potential side effects.
AZT is used to treat people infected with H.I.V. and has been particularly effective in reducing the transmission of the virus from pregnant
women to their fetuses. One two-year
study found that a short course of
AZT treatment administered to
women who did not breast-feed their
babies reduced transmission of the
virus by 50 percent.
"There is toxicity, but this is not a
sweet, this is a drug," said Dr. Joseph Perriens, who heads the care
and support program of the United
Nations AIDS program in Geneva.
"To combat a fatal disease, it is
perfectly acceptable to use drugs
slightly more toxic than an aspirin,"
he said. "AZT is a valuable therapeutic drug. Its efficacy is a very important consideration and needs to be
taken into account."
Doctors, advocates for AIDS patients and executives of the company
that produces AZT, Glaxo Wellcome,
have urged the government to review the scientific literature. The
government, which has vowed to battle AIDS aggressively, has promised
that it will make such a review.
But Ms. Tshabalala-Msimang said
that even if AZT proves to be safe, it
is too expensive to distribute. An
estimated 3.6 million of South Africa's 44 million people are infected
with H.I.V. And treating all those
people with AZT would cost the government 10 times what it currently
spends on health care, she said.
She said the government is also
looking into a new drug that researchers say is less costly and
more effective than AZT in reducing
mother-to-child transmission. The
cost for two doses of the drug, nevirapine, is about $4, compared with
$268 for the AZT regimen used in
developing countries and $815 for the
much longer and more complicated
course used in the United States and
other developed countries.