Predose infant nevirapine concentration with the two-dose intrapartum neonatal nevirapine regimen: association with timing of maternal intrapartum nevirapine dose.
OBJECTIVE
To evaluate cord blood and predose nevirapine concentrations in infants exposed to the two-dose intrapartum neonatal nevirapine regimen.


METHODS
The authors obtained plasma samples for nevirapine assay from cord blood and just prior to the 48-hours to 72-hours after birth neonatal nevirapine dose from a subset of infants participating in PACTG 316, a randomized, placebo-controlled trial of the two-dose intrapartum neonatal nevirapine regimen added to standard antiretroviral therapy.


RESULTS
Nevirapine concentrations were measured in 109 cord blood samples and 149 predose samples. Cord blood nevirapine concentrations were below the target concentration of 100 ng/mL (10-times the in vitro IC(50) of nevirapine against wild-type HIV) in eight (7%) of 109 infants (95% confidence interval [CI], 3%-14%); the concentrations in six of these infants were below the assay limit of quantitation. Predose infant nevirapine concentrations were below 100 ng/mL in 23 (15%) of 149 infants (95% CI, 10%-22%); the concentrations in 13 of these infants were below the assay limit of quantitation. Lower predose nevirapine concentrations were associated with lower cord blood concentrations and a shorter interval between maternal dosing and delivery. All but one of the infants with predose nevirapine concentrations below the assay limit of quantitation were born less than 2 hours after maternal dosing.


CONCLUSIONS
Infants born less than 2 hours after maternal nevirapine dosing during labor should receive a dose of nevirapine immediately after birth in addition to the standard infant dose at 48 to 72 hours.
Mirochnick
Mark
M
Boston University School of Medicine, Boston Medical Center, 91 Concord Street, 6th Floor, Boston, MA 02118, USA. mark.m@bu.edu
Dorenbaum
Alejandro
A
Blanchard
Suzette
S
Cunningham
Coleen K
CK
Gelber
Richard D
RD
Mofenson
Lynne
L
Culnane
Mary
M
Sullivan
John L
JL
D000328:Adult; D019380:Anti-HIV Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D001444:Bahamas; D001938:Brazil; D004311:Double-Blind Method; D005060:Europe; D005260:Female; D005312:Fetal Blood / Q000378:metabolism; D015658:HIV Infections / Q000097:blood / Q000188:drug therapy* / Q000378:metabolism; D015497:HIV-1; D006801:Humans; D007231:Infant, Newborn; D019829:Nevirapine / Q000008:administration & dosage / Q000493:pharmacokinetics*; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000097:blood / Q000188:drug therapy* / Q000378:metabolism; D014481:United States
D019380:Anti-HIV Agents; D019829:Nevirapine