The pharmacokinetics and safety of zidovudine in the third trimester of pregnancy for women infected with human immunodeficiency virus and their infants: phase I acquired immunodeficiency syndrome clinical trials group study (protocol 082). Zidovudine Collaborative Working Group.

OBJECTIVES

We measured the pharmacokinetics and safety of zidovudine in pregnant women infected with human immunodeficiency virus and their offspring.

STUDY DESIGN

Asymptomatic human immunodeficiency virus-infected women with uncomplicated singleton gestations (28 to 36 weeks) underwent parenteral and oral zidovudine treatment during pregnancy and labor. Maternal and neonatal drug levels were measured at delivery and sequentially for 48 hours. Infants were followed up for 18 months.

RESULTS

The total body clearance (26.3 +/- 10.1 ml/min/kg), mean terminal elimination phase zidovudine half-life (1.3 +/- 0.2 hours), and urinary zidovudine recovery were similar to values in nonpregnant adults. Essentially equivalent zidovudine levels in the mother and neonate at delivery implied little, if any, fetal zidovudine metabolism. The half-life of zidovudine in the neonates was tenfold that of the mother. No significant adverse effects were noted in the infant at birth or on follow-up.

CONCLUSIONS

In both mothers and infants the drug appeared safe and well tolerated with no significant hematologic abnormalities.