Concentrations of protease inhibitors in cord blood after in utero exposure.

OBJECTIVE: To determine the concentrations of protease inhibitors in cord blood after prenatal protease inhibitor use by pregnant women. DESIGN: Retrospective analysis of samples collected in a clinical trial. METHODS: Protease inhibitor concentrations were measured in cord blood samples collected from women enrolling in the PACTG 316 study who were receiving prenatal protease inhibitor antiretroviral therapy. RESULTS: In cord blood samples from 68 women treated with protease inhibitors during pregnancy, the concentration of these drugs was below the assay lower limit of detection in most samples, including all samples from women receiving indinavir (n = 21) and saquinavir (n = 8), 5 of 6 samples (83%) from women receiving ritonavir and 24 of 38 samples (63%) from women receiving nelfinavir. CONCLUSIONS: Low protease inhibitor concentrations in the fetus decrease the likelihood of teratogenic and toxic effects of these drugs but could fail to provide protection from transplacental or intrapartum transmission of HIV-1.

Two-dose intrapartum/newborn nevirapine and standard antiretroviral therapy to reduce perinatal HIV transmission: a randomized trial.

CONTEXT: A 2-dose intrapartum/newborn nevirapine regimen reduced perinatal human immunodeficiency virus (HIV) transmission in Ugandan women not receiving antenatal antiretroviral therapy (ART). However, it is unknown whether the addition of the 2-dose nevirapine regimen to standard ART would further reduce perinatal HIV transmission. OBJECTIVE: To determine whether a 2-dose nevirapine regimen can decrease perinatal transmission of HIV in nonbreastfeeding women receiving standard ART. DESIGN AND SETTING: International, blinded, placebo-controlled, phase 3 trial enrolling women between May 1997 and June 2000 at clinical sites providing care for HIV infection throughout the United States, Europe, Brazil, and the Bahamas. PARTICIPANTS: A total of 1270 women received nevirapine (n = 642) or placebo (n = 628). Infants were followed up for 6 months to determine HIV-infection status, which was available for 1248 deliveries. INTERVENTION: A 200-mg dose of oral nevirapine to women after onset of labor and a 2-mg/kg dose of oral nevirapine to newborns between 48 and 72 hours after birth. MAIN OUTCOME MEASURES: Detection of HIV infection in infants and grade 3 and 4 toxic effects in women and newborns. RESULTS: After review by the data and safety monitoring board, the trial was stopped early because the overall transmission rates were significantly lower than assumed for the study design. Antenatal ART included zidovudine alone in 23%; combinations without protease inhibitors in 36%; and combinations with protease inhibitors in 41%. Thirty-four percent of women had elective cesarean delivery. No significant safety concerns were identified for women or infants. Detection of HIV infection occurred in 9 (1.4%; 95% confidence interval [CI], 0.6%-2.7%) of 631 nevirapine group deliveries and 10 (1.6%; 95% CI, 0.8%-2.9%) of 617 placebo group deliveries. The 95% CI for the difference in transmission rate (-0.2) between the 2 study arms ranged from -1.5% in favor of nevirapine to 1.2% in favor of placebo (P =.82, Fisher exact test). The transmission rate was higher in women with lower baseline CD4 cell counts and higher delivery HIV RNA levels, but there was no significant difference between treatment arms in any subgroup. CONCLUSION: Risk of perinatal HIV transmission was low and no benefit from additional intrapartum/newborn nevirapine was demonstrated when women received prenatal care and antenatal ART, and elective cesarean section was made available.