Drug prevents mother-fetus HIV transmission - Retrovir, or zidovudine, approved for use in pregnant women with HIV virus

FDA Consumer, Nov, 1994

The anti-AIDS drug Retrovir (zidovudine, commonly called AZT) was approved Aug. 8 for a new use: preventing transmission of HIV from infected pregnant women to their babies.

Last July 28, FDA's Antiviral Drugs Advisory Committee unanimously recommended amending Retrovir's labeling to include this use.

Data supporting the new use comes from a federally sponsored study to determine whether Retrovir reduces the risk of passing HIV, the virus that causes AIDS, from infected mothers to their infants either before or during birth.

The study was halted when a planned interim review of the data found that pregnant women taking Retrovir transmitted the virus to their babies at a rate approximately two-thirds lower than those not taking the drug. The transmission rate for women given a placebo was 25.5 percent, while those given Retrovir infected their babies at a rate of 8.3 percent. A long-term follow-up study of babies exposed to AZT is under way.

During the randomized, placebo-controlled trial, HIV-infected women received 500 milligrams of Retrovir a day orally during pregnancy and continuous intravenous infusion of Retrovir during labor. Treatment was begun between 14 and 34 weeks after conception. Newborns received oral Retrovir within 24 hours after birth and for the next six weeks. Women in the study were not treated during the first trimester of pregnancy. Also, women who had previously taken Retrovir or whose CD4 cell counts were below 200 were not eligible for the study.

Reported side effects included reversible mild anemia in some infants.

Retrovir is manufactured by Burroughs Wellcome Co. of Research Triangle Park, N.C.