title: Factors associated with the successful modification of antiretroviral therapy. HIV Outpatient Study Investigators.
abstract: OBJECTIVE
  To assess the characteristics of medication regimen modification and the influence of a commercial genotypic resistance assay on the short-term (3-12 weeks) viral load response (> or = 0.5 log reduction) in HIV-1-infected patients extensively treated with antiretroviral therapy (ART).
  
  
  METHODS
  A nested cohort study was performed in two clinics from the HIV Outpatient Study of 96 persons with a HIV-1 viral load of 10(4) log copies/ml or greater taking at least two antiretroviral medications.
  
  
  RESULTS
  Successful modification was associated with adding at least two new medications [relative risk (RR), 1.5; 95% confidence interval (CI), 1.1-2.2], adding a drug from a previously unused class of agents (RR, 2.0; CI, 1.4-2.9), the initiation of a non-nucleoside reverse transcriptase inhibitor (NNRTI) (RR, 1.7; CI, 1.2-2.4), but not substituting a protease inhibitor or the use of a commercial genotypic resistance assay.
  
  
  CONCLUSIONS
  Incorporating a drug from a previously unused class or changing at least two new medications, but, within the confines of this study, not using a commercial genotypic resistance assay, was associated with the successful modification of ART as measured by a reduction in viral load.
authors.affiliation: Epidemiology Branch, Division of HIV/AIDS Prevention Surveillance and Epidemiology, National Center for HIV, STD, and TB Prevention, Centers for Disease Control, Atlanta, GA 30333, USA. pew6@cdc.gov
authors.forename: P J
authors.initials: PJ
authors.lastname: Weidle
authors.forename: K A
authors.initials: KA
authors.lastname: Lichtenstein
authors.forename: A C
authors.initials: AC
authors.lastname: Moorman
authors.forename: J C
authors.initials: JC
authors.lastname: Von Bargen
authors.forename: K S
authors.initials: KS
authors.lastname: Greenberg
authors.forename: F J
authors.initials: FJ
authors.lastname: Palella
authors.forename: S D
authors.initials: SD
authors.lastname: Holmberg
mesh_terms: D000328:Adult; D000368:Aged; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D018791:CD4 Lymphocyte Count; D015331:Cohort Studies; D004352:Drug Resistance, Microbial / Q000235:genetics; D004359:Drug Therapy, Combination; D005260:Female; D005838:Genotype; D006678:HIV / Q000187:drug effects* / Q000235:genetics; D015658:HIV Infections / Q000188:drug therapy* / Q000453:epidemiology / Q000821:virology; D017320:HIV Protease Inhibitors / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D018894:Reverse Transcriptase Inhibitors / Q000627:therapeutic use; D019562:Viral Load
chemical_list: D019380:Anti-HIV Agents; D017320:HIV Protease Inhibitors; D018894:Reverse Transcriptase Inhibitors