Drug to stop HIV spread to babies may harm moms
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Nevirapine is reducing the chances that mothers with AIDS will pass the disease to their unborn children, but the drug may cause problems later on. CNN's Christy Feig explains.
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SAN FRANCISCO, California (AP) -- The treatment used in poor countries to prevent the spread of HIV from mothers to their babies may have a serious drawback: It can make the women resistant to the AIDS drugs they may need later on, disturbing new research shows.
In impoverished areas where the risk is greatest, researchers have settled on a simple, one-time treatment for HIV-infected pregnant women to keep them from passing the virus to their newborns. The treatment, using the drug nevirapine, is easy, inexpensive and effective, typically cutting the risk of HIV transmission in half.
However, new findings presented Monday at the 11th Annual Retrovirus Conference suggest a potentially important trade-off for the mother that could complicate her later treatment, if it is available.
Earlier studies had suggested that the single dose of the drug might make the virus impervious to later treatment, but until now there has been no clear evidence whether the theoretical risk is real.
"These are crucial data that the world has been waiting for," said Dr. Scott Hammer of Columbia University.
One study, conducted in South Africa, found that 39 percent of HIV-infected women who get nevirapine during pregnancy go on to harbor virus that is resistant to the drug. Another, done in Thailand, shows the potential consequence: The mothers who eventually need drug treatment for their infection are much less likely than usual to respond to it.
Kate Carr, president of the Elizabeth Glaser Pediatric AIDS Foundation, said the discovery is not a complete surprise, since earlier studies have hinted at that problem. And for now, there is no easy way around it.
"The sad reality is, we do not have another option in most places, either for mothers or babies," Carr said.
She said the foundation is the single largest provider of treatment to prevent mother-to-child AIDS transmission in Africa and other poor parts of the world.
The World Health Organization estimates that 40 million people are infected with the AIDS virus, 95 percent of them in developing countries. In some African countries, 40 percent of pregnant women have the virus. Last year, an estimated 700,000 children caught HIV.
In the United States and Europe, pregnant women with HIV are routinely given combinations of powerful AIDS drugs throughout their pregnancy. This reduces the risk of passing the virus on at birth to near zero and minimizes the chance of developing resistance.
In Africa and other places where this approach is not considered practical, the WHO has recommended giving a single dose of nevirapine when labor starts and then giving a second pill to the baby two days after birth.
"We've heard a lot about nevirapine resistance, but it should be remembered that it does work," said Dr. Neil Martinson of Johns Hopkins University. About 8 percent of babies catch the virus after nevirapine, compared with about 20 percent of those who get no treatment.
Doctors at the conference said several alternatives are under consideration:
• Giving pregnant women three AIDS drugs combined into a single pill.
• Giving no drug to the mother and treating only the child after birth.
• Giving the mother a month of two or three AIDS drugs after delivery.
• Experimenting with alternative single drugs that might produce less resistance.
"The solution can't be to infect the babies," said Dr. Gonzague Jourdain of Harvard School of Public Health, who was involved in the Thai study.
In that study, doctors found that women who had gotten nevirapine during pregnancy were much less likely to do well on a standard three-drug regimen if they developed AIDS. Three-quarters responded to treatment if they had never received nevirapine during pregnancy, compared with just one-third of those who had developed resistant virus because of their pregnancy treatment.
Copyright 2004 The
Associated Press. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.
