title: Intrapartum exposure to nevirapine and subsequent maternal responses to nevirapine-based antiretroviral therapy.
abstract: BACKGROUND
  A single intrapartum dose of nevirapine for the prevention of mother-to-child transmission of human immunodeficiency virus (HIV) leads to the selection of resistance mutations. Whether there are clinically significant consequences in mothers who are subsequently treated with a nevirapine-containing regimen is unknown.
  
  
  METHODS
  We randomly assigned 1844 women in Thailand who received zidovudine during the third trimester of pregnancy to receive intrapartum nevirapine or placebo. In the postpartum period, 269 of the women with a CD4 count below 250 cells per cubic millimeter began a nevirapine-containing antiretroviral regimen. Plasma samples were obtained 10 days post partum and analyzed for resistance mutations. Plasma HIV type 1 (HIV-1) RNA was measured before the initiation of therapy and three and six months thereafter.
  
  
  RESULTS
  After six months of therapy, the HIV-1 RNA level was less than 50 copies per milliliter in 49 percent of the women who had received intrapartum nevirapine, as compared with 68 percent of the women who had not received intrapartum nevirapine (P=0.03). Resistance mutations to nonnucleoside reverse-transcriptase inhibitors were detectable in blood samples obtained 10 days post partum from 32 percent of the women who had received intrapartum nevirapine; the most frequent mutations were K103N, G190A, and Y181C. Among the women who had received intrapartum nevirapine, viral suppression was achieved at six months in 38 percent of those with resistance mutations and 52 percent of those without resistance mutations (P=0.08). An HIV-1 RNA level at or above the median of 4.53 log10 copies per milliliter before therapy and intrapartum exposure to nevirapine were independently associated with virologic failure. After six months of therapy, there was no significant difference between groups in the CD4 count (P=0.65).
  
  
  CONCLUSIONS
  Women who received intrapartum nevirapine were less likely to have virologic suppression after six months of postpartum treatment with a nevirapine-containing regimen. Our data suggest the need for strategies to maximize the benefits of both antiretroviral prophylaxis against mother-to-child transmission of HIV and antiretroviral therapy for mothers.
authors.affiliation: Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, USA. gonzague@phpt.org
authors.forename: Gonzague
authors.initials: G
authors.lastname: Jourdain
authors.forename: Nicole
authors.initials: N
authors.lastname: Ngo-Giang-Huong
authors.forename: Sophie
authors.initials: S
authors.lastname: Le Coeur
authors.forename: Chureeratana
authors.initials: C
authors.lastname: Bowonwatanuwong
authors.forename: Pacharee
authors.initials: P
authors.lastname: Kantipong
authors.forename: Pranee
authors.initials: P
authors.lastname: Leechanachai
authors.forename: Surabhon
authors.initials: S
authors.lastname: Ariyadej
authors.forename: Prattana
authors.initials: P
authors.lastname: Leenasirimakul
authors.forename: Scott
authors.initials: S
authors.lastname: Hammer
authors.forename: Marc
authors.initials: M
authors.lastname: Lallemant
mesh_terms: D000328:Adult; D044966:Anti-Retroviral Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D004311:Double-Blind Method; D024882:Drug Resistance, Viral / Q000235:genetics; D004359:Drug Therapy, Combination; D005260:Female; D005500:Follow-Up Studies; D005838:Genotype; D015658:HIV Infections / Q000188:drug therapy* / Q000517:prevention & control / Q000635:transmission; D015497:HIV-1 / Q000235:genetics; D006801:Humans; D007743:Labor, Obstetric; D016015:Logistic Models; D009154:Mutation; D019829:Nevirapine / Q000008:administration & dosage / Q000627:therapeutic use*; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000188:drug therapy*; D011263:Pregnancy Trimester, Third; D012367:RNA, Viral / Q000097:blood; D012307:Risk Factors; D017211:Treatment Failure; D019562:Viral Load; D015215:Zidovudine / Q000627:therapeutic use
chemical_list: D044966:Anti-Retroviral Agents; D012367:RNA, Viral; D015215:Zidovudine; D019829:Nevirapine