Head-to-Head Study Finds Two Drug Regimens Each Effective in Preventing Mother-to-Child HIV Transmission

ALEXANDRIA, Va. -- Two different drug regimens each were found to be effective and safe for the prevention of mother-to-child transmission of HIV, according to the results from the South African Intrapartum Nevirapine Trial (SAINT), published in the March 1, 2003 issue of the Journal of Infectious Diseases.

SAINT adds to the body of evidence that demonstrates the safety and efficacy of short-course antiretroviral drug regimens for the prevention of mother-to-child transmission of HIV. More significantly, the trial is the first direct comparison of two regimens that previously were studied separately and found to be effective in preventing HIV transmission from mother to child, particularly in developing countries.

In less than a decade since the introduction in the United States of antiretroviral drugs to prevent HIV from being transmitted from infected mothers to infants, transmission rates have dropped from 25 percent of all babies of HIV positive mothers acquiring HIV to less than 2 percent. However, this success has not been mirrored in the developing world, due in large part to the high costs associated with antiretroviral drugs.

In this head-to-head study of zidovudine and lamivudine (often considered the "gold standard" regimen for the prevention of paranatal HIV infection) versus the far less expensive nevirapine, both regimens were effective at preventing HIV transmission from mother to child. Researchers enrolled HIV-infected pregnant women in an open-label short course antiretroviral regimen of either nevirapine or multi-dose zidovudine and lamivudine. The overall estimated HIV infection rates by eight weeks in the 1,307 babies born were 12.3 percent for nevirapine and 9.3 percent for zidovudine and lamivudine; these differences are not statistically significant.

Since the nevirapine regimen requires fewer doses and thus is considerably less expensive, it is a far more appealing option for resource-limited countries, where more than 90 percent of mother-to-child HIV infections worldwide occur. However, since resistance to nevirapine may develop rapidly, the final answer on the best regimen remains unclear.

Source: Infectious Diseases Society of America