title: Discontinuation rates for protease inhibitor regimens containing ritonavir 600 mg versus ritonavir 400 mg plus saquinavir 400 mg.
abstract: OBJECTIVE
  A retrospective study was performed to determine whether twice-daily ritonavir 400 mg plus twice-daily saquinavir 400 mg (ritonavir 400/saquinavir 400) was better tolerated than ritonavir 600 mg twice daily (ritonavir 600). A secondary objective was to determine whether the rate of discontinuation due to therapeutic failure differed between the two ritonavir regimens.
  
  
  METHODS
  The study was a retrospective chart review. Data collected included ritonavir dose; length of ritonavir therapy; reason for discontinuation; HIV-1 RNA prior to and at discontinuation of ritonavir therapy; CD4+ count; and antiretroviral therapy prior to, concomitant with, and initiated after ritonavir therapy.
  
  
  METHODS
  Patient charts were reviewed in a university teaching hospital clinic.
  
  
  METHODS
  Patients were identified through a search of the pharmacy database from December 18, 1995, to December 18, 1997. Patients were > 18 years old, but not restricted by gender or race.
  
  
  METHODS
  The main outcome measures were frequency of discontinuation of ritonavir due to intolerance or due to lack of therapeutic efficacy.
  
  
  RESULTS
  The search identified 116 patients, including 57 patients taking ritonavir 400/saquinavir 400 and 54 patients taking ritonavir 600. Five patients on other ritonavir regimens were excluded. Significantly fewer patients receiving ritonavir 400/saquinavir 400 (14%) discontinued ritonavir due to intolerance compared with ritonavir 600 (37%; p = 0.002). Discontinuations due to therapeutic failure were not significantly different: 8.8% for ritonavir 400/saquinavir 400 and 7.4% for ritonavir 600, despite the fact that ritonavir/saquinavir therapy followed another protease inhibitor in 41 patients (73.2%) compared with 12 patients (24.5%) for ritonavir 600 (p = 0.001).
  
  
  CONCLUSIONS
  Ritonavir 400/saquinavir 400 is better tolerated than ritonavir 600.
authors.affiliation: University of North Carolina Hospitals and Clinics, Chapel Hill 27514, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: Rublein
authors.forename: J J
authors.initials: JJ
authors.lastname: Eron
authors.forename: J D
authors.initials: JD
authors.lastname: Butts
authors.forename: R H
authors.initials: RH
authors.lastname: Raasch
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use; D003967:Diarrhea / Q000139:chemically induced; D004305:Dose-Response Relationship, Drug; D004341:Drug Evaluation; D004358:Drug Therapy / Q000706:statistics & numerical data; D004359:Drug Therapy, Combination; D005260:Female; D005767:Gastrointestinal Diseases / Q000139:chemically induced; D015658:HIV Infections / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009325:Nausea / Q000139:chemically induced; D011480:Protease Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D012189:Retrospective Studies; D019438:Ritonavir / Q000009:adverse effects / Q000627:therapeutic use*; D019258:Saquinavir / Q000009:adverse effects / Q000627:therapeutic use*; D016896:Treatment Outcome; D014839:Vomiting / Q000139:chemically induced
chemical_list: D019380:Anti-HIV Agents; D011480:Protease Inhibitors; D019258:Saquinavir; D019438:Ritonavir