title: Viral load outcome of non-nucleoside reverse transcriptase inhibitor regimens for 2203 mainly antiretroviral-experienced patients.
abstract: OBJECTIVE
  To assess the factors associated with virologic response to non-nucleoside reverse transcriptase inhibitor (NNRTI)-containing regimens in a large clinic cohort.
  
  
  METHODS
  Inception cohort.
  
  
  METHODS
  HIV clinics in Europe
  
  
  METHODS
  We identified all patients in EuroSIDA who began a regimen including either nevirapine or efavirenz (not both) after July 1997 and for whom pre-therapy viral load and CD4 cell count were known.
  
  
  METHODS
  Virological failure.
  
  
  RESULTS
  A total of 1325 patients initiated nevirapine and 878 efavirenz. Respectively, median start dates were October 1998 and May 1999. Other factors at baseline, including CD4 cell count, viral load, previous AIDS, previous antiretroviral drug use and make-up of the NNRTI-containing regimen were all approximately similar between the nevirapine and efavirenz groups. A total of 669 patients experienced virological failure during follow-up. In a Cox model, less protease inhibitors and nucleoside reverse transcriptase inhibitors (NRTIs) previously used, higher CD4 nadir, lower viral load at baseline, a previous AIDS diagnosis and less NRTIs in the regimen were associated with lower risk of virological failure. The relative hazard of virological failure comparing those on efavirenz with those on nevirapine was 0.57 (95% confidence interval, 0.47-0.69; P < 0.0001).
  
  
  CONCLUSIONS
  The difference in virologic outcome between those using nevirapine and efavirenz in this almost entirely drug-experienced population could reflect differences in effectiveness of the drugs in this setting but, despite the similarity between groups at baseline, bias cannot be excluded as an explanation. Replication of these findings in randomized trials and other cohort studies is required.
authors.affiliation: Royal Free Centre for HIV Medicine and Department of Primary Care and Population Sciences, Royal Free and University College, London, UK. a.phillips@pcps.ucl.ac.uk
authors.forename: A N
authors.initials: AN
authors.lastname: Phillips
authors.forename: C
authors.initials: C
authors.lastname: Pradier
authors.forename: A
authors.initials: A
authors.lastname: Lazzarin
authors.forename: B
authors.initials: B
authors.lastname: Clotet
authors.forename: F D
authors.initials: FD
authors.lastname: Goebel
authors.forename: P
authors.initials: P
authors.lastname: Hermans
authors.forename: F
authors.initials: F
authors.lastname: Antunes
authors.forename: B
authors.initials: B
authors.lastname: Ledergerber
authors.forename: O
authors.initials: O
authors.lastname: Kirk
authors.forename: J D
authors.initials: JD
authors.lastname: Lundgren
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D015331:Cohort Studies; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D005060:Europe; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology; D015497:HIV-1 / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018894:Reverse Transcriptase Inhibitors / Q000627:therapeutic use*; D016896:Treatment Outcome; D019562:Viral Load
chemical_list: D019380:Anti-HIV Agents; D018894:Reverse Transcriptase Inhibitors