title: Association of Nevirapine Levels with Rash or Hepatotoxicity Among HIV-Infected Thai Women.
abstract: BACKGROUND
  We performed a nested case-control study of Thai women prescribed nevirapine-based antiretroviral therapy (ART) to determine if development of rash or hepatotoxicity during the first 24 weeks of treatment is associated with plasma nevirapine concentrations.
  
  
  METHODS
  From May 2005-January 2007, we enrolled 217 women initiating nevirapine-based ART in Thailand. Cases (n = 54) were women who during the first 24 weeks of treatment with nevirapine developed rash (any grade, n = 42) or hepatotoxicity (≥grade 2, n = 22, [10 had both]). Controls were the next enrolled woman who was confirmed not to meet the case definition during the first 24 weeks. Nevirapine concentrations after the two week lead-in dose of 200 mg once daily were compared between cases and controls by Wilcoxon rank-sum tests.
  
  
  RESULTS
  We found no difference in Week 2 pre-dose nevirapine concentrations: cases median = 3,528 ng/mL (n = 24), controls median = 3,150ng/mL (n = 30), p = 0.5. Cases had higher post-dose nevirapine concentrations (median = 6,150 ng/mL, n = 21) than controls (median = 4,746 ng/mL, n = 20, p = 0.02). When limited to cases who developed a rash at Week 2, we found no differences in the pre-dose (median = 3,270 ng/mL, n = 12, p = 0.9) or post-dose nevirapine concentration (median = 5,443 ng/mL, n = 9, p = 0.4) compared with controls.
  
  
  CONCLUSIONS
  We cannot conclude definitively that nevirapine concentrations at two weeks of therapy are associated with rash or hepatotoxicity. It is unlikely that therapeutic drug monitoring at that time will improve identification of patients at risk for rash or hepatotoxicity.
authors.affiliation: Department of Preventive and Social Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Winai
authors.initials: W
authors.lastname: Ratanasuwan
authors.forename: Tavatchai
authors.initials: T
authors.lastname: Jariyasethpong
authors.forename: Thanomsak
authors.initials: T
authors.lastname: Anekthananon
authors.forename: Poj
authors.initials: P
authors.lastname: Intalapaporn
authors.forename: Supornchai
authors.initials: S
authors.lastname: Kongpatanakul
authors.forename: Piyapat
authors.initials: P
authors.lastname: Pongnarin
authors.forename: Punneeporn
authors.initials: P
authors.lastname: Wasinrapee
authors.forename: Nartlada
authors.initials: N
authors.lastname: Chantharojwong
authors.forename: Boonyos
authors.initials: B
authors.lastname: Raengsakulrach
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Peters
authors.forename: Janet
authors.initials: J
authors.lastname: McNicholl
authors.forename: Michelle S
authors.initials: MS
authors.lastname: McConnell
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Weidle
keywords: Adverse effect; Thailand.; antiretroviral; hepatotoxicity; nevirapine; rash