Persistence of nevirapine exposure during the postpartum period after intrapartum single-dose nevirapine in addition to zidovudine prophylaxis for the prevention of mother-to-child transmission of HIV-1.
OBJECTIVE
To determine nevirapine (NVP) plasma levels during the postpartum period after a single intrapartum NVP dose for the prevention of mother-to-child transmission.


METHODS
Plasma samples at delivery and during days 8 to 45 postpartum were obtained from HIV-infected Thai women who received an intrapartum NVP dose in the Perinatal HIV Prevention Clinical Trial-2 (PHPT-2) for the prevention of perinatal HIV transmission. These data were combined with NVP concentration data from 2 phase 1 studies of NVP for a population analysis.


RESULTS
The median NVP level fell to 68 ng/mL (range: <50-228, n = 43) 8 to 14 days after dosing and to 51 ng/mL (range: <50-166, n = 25) between 15 and 21 days. During the second and third weeks postpartum, NVP levels were below the limit of quantitation in 23% and 44% of samples, respectively. Between 21 and 45 days, no sample had a quantifiable NVP concentration. A simulation derived from the population analysis predicts that NVP concentration falls to less than 10 ng/mL in 5% of women by 11 days, in 50% of women by 17.5 days, and in 95% of women by 28 days.


CONCLUSIONS
Significant NVP concentrations remained for up to 20 days in these Thai women. To ensure that coverage is maintained until NVP concentrations fall to nonsuppressive levels, 1 month of additional antiretroviral treatment after delivery should be considered to prevent the emergence of resistant viruses.
Cressey
Tim R
TR
Harvard School of Public Health, Boston, MA, USA. tim@phpt.org
Jourdain
Gonzague
G
Lallemant
Marc J
MJ
Kunkeaw
Suparat
S
Jackson
J Brooks
JB
Musoke
Philippa
P
Capparelli
Edmund
E
Mirochnick
Mark
M
D000293:Adolescent; D000328:Adult; D019380:Anti-HIV Agents / Q000097:blood / Q000494:pharmacology / Q000627:therapeutic use; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000517:prevention & control / Q000635:transmission*; D006801:Humans; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control*; D019829:Nevirapine / Q000097:blood* / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use*; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000188:drug therapy*; D013785:Thailand; D015215:Zidovudine / Q000494:pharmacology / Q000627:therapeutic use*
D019380:Anti-HIV Agents; D015215:Zidovudine; D019829:Nevirapine