The South African Health Ministry said Tuesday that it would not retreat from using antiretroviral medicines to block the transmission of HIV from mothers to children at birth, even though the country's health regulators this week warned about the use of one of the most popular of those drugs, nevirapine.

Ministry spokesman Sibani Mngadi said health officials would need to review the nevirapine program in light of Monday's ruling by the Medicines Control Council before deciding how to continue administering the medicine, which has blocked the infection of thousands of babies born to mothers with HIV.

He said ending or substantially curbing the program was not an option under consideration. "We are not going to stop our efforts to stop mother-to-child transmission," Mngadi said.

The Medicines Control Council, which oversees the use of pharmaceutical drugs in South Africa, reported Monday that a single dose of nevirapine at birth could cause mother and child to become resistant to the drug, which is a staple of the combination drug therapies that are the preferred long-term treatment for AIDS.

The council recommended that to prevent resistance, nevirapine should be used only with other antiretroviral medicines. Mngadi said the Health Ministry was considering whether to use combination therapies in place of nevirapine alone.

The South African government fought the use of nevirapine on the grounds that it might be dangerous, until AIDS activists won a court case forcing its implementation. Its use is now common throughout South Africa, where transmission rates at birth have been cut dramatically.

-- Craig Timberg