title: Using of nevirapine is associated with intermediate and reduced response to etravirine among HIV-infected patients who experienced virologic failure in a resource-limited setting.
abstract: BACKGROUND
  Non-nucleoside reverse transcriptase inhibitor (NNRTI)-based regimens have been extensively used for treatment of HIV infection in resource-limited settings. Treatment options after failing an initial regimen are limited because of cross-resistance of NNRTIs.
  
  
  OBJECTIVE
  To determine the factors associated with reduced response to etravirine among patients with virological failure.
  
  
  METHODS
  A retrospective study was conducted. We stratified patients into two groups by the total weighted scores of etravirine-resistance-associated mutations (ETV-RAMs), highest response (score 0-2, N=123) and intermediate and reduced response (score > or =2.5, N=61). Factors associated with a score of > or =2.5 were evaluated.
  
  
  RESULTS
  There were 184 patients with mean (SD) age of 42 (9) years old and 60% were males. Of all, 68% used NNRTI in the failing regimen and 51% used stavudine/lamivudine as a backbone. Common ETV-RAMs included Y181C (27%), G190A (17%), and K101E (10%). Higher proportion of K101E, K101P, Y181C, G190S, and M230L were found in patients with a score of > or =2.5 (p<0.05, all). By univariate logistic regression, using protease inhibitor (OR 0.22, 95% CI 0.07-0.67), nevirapine (OR 10.56, 95% CI 4.04-27.74), and efavirenz (OR 2.91, 95% CI 1.01-2.51) in the current regimen were associated with a score of > or =2.5. By multiple logistic regression, only using nevirapine was associated with a score of > or =2.5 (OR 7.61, 95% CI 2.40-24.06).
  
  
  CONCLUSIONS
  Using nevirapine in the failing regimen was associated with intermediate and reduced response to ETV. The recommendation of using nevirapine as a preferred NNRTI should be re-considered in resource-limited settings where efavirenz is accessible.
authors.affiliation: Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, 270 Rama VI Road, Bangkok 10400, Thailand. rasal@mahidol.ac.th
authors.forename: Sasisopin
authors.initials: S
authors.lastname: Kiertiburanakul
authors.forename: Surasak
authors.initials: S
authors.lastname: Wiboonchutikul
authors.forename: Chonlaphat
authors.initials: C
authors.lastname: Sukasem
authors.forename: Wasun
authors.initials: W
authors.lastname: Chantratita
authors.forename: Somnuek
authors.initials: S
authors.lastname: Sungkanuparph
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D023241:Antiretroviral Therapy, Highly Active / Q000379:methods*; D003906:Developing Countries; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology; D015497:HIV-1 / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D020125:Mutation, Missense; D019829:Nevirapine / Q000627:therapeutic use*; D009570:Nitriles; D011724:Pyridazines / Q000627:therapeutic use*; D011743:Pyrimidines; D012189:Retrospective Studies; D013785:Thailand; D016896:Treatment Outcome
chemical_list: D019380:Anti-HIV Agents; D009570:Nitriles; D011724:Pyridazines; D011743:Pyrimidines; C451734:etravirine; D019829:Nevirapine