A joint Uganda-US study has found that a single dose of nevirapine given at the onset of labour is almost 50% more effective than four weeks of AZT treatment at preventing transmission of HIV from mother to baby, and 70% cheaper.
Interim results from the study, sponsored by the US National Institute of Allergy and Infectious Diseases (NIAID), demonstrate that a single oral dose of the antiretroviral drug nevirapine (NVP) given to an HIV-infected woman in labor and another to her baby within three days of birth reduces the transmission rate by half compared to a similar short course of AZT. If implemented widely in developing countries, this intervention potentially could prevent some 300,000 to 400,000 newborns per year from beginning life infected with HIV.
The study, known as HIVNET 012, compared the safety and efficacy of two different short-course regimens of antiviral drugs administered late in pregnancy. The women were assigned at random to receive either a 200-mg dose of oral nevirapine at the onset of labor, followed by a 2-mg/kg oral dose given to their babies within three days of birth; or a 600-mg dose of AZT at the onset of labour, and 300-mg doses every three hours thereafter during labour. The infants born to mothers in the AZT group received 4 mg/kg given twice daily for the first week of life. Both drugs appeared to be safe and well-tolerated.
Nevirapine was markedly more effective. At 14 to 16 weeks of age, 13.1 percent of infants who received nevirapine were infected with HIV, compared with 25.1 percent of those in the AZT group.
"In this study, the short-course nevirapine regimen resulted in a 47 percent reduction in mother-to-infant HIV transmission compared with a short course of AZT. The implications of this study for developing countries, where 95 percent of the AIDS epidemic is occurring, are profound," says Brooks Jackson, MD, the lead US investigator on the trial.
Based on United States prices, the nevirapine treatment was 200 times cheaper than long-term AZT use, and 70 percent cheaper than short-term AZT treatment.