title: Olsalazine versus sulphasalazine for relapse prevention in ulcerative colitis: a multicenter study.
abstract: OBJECTIVE
  To compare the relapse-preventing effect and the frequency of adverse events of olsalazine and sulphasalazine in sulphasalazine-tolerant patients with ulcerative colitis.
  
  
  METHODS
  Patients in remission, with at least two episodes of active disease during the last 5 yr, were randomized to 2 g of sulphasalazine or 1 g of olsalazine daily and were followed for 6-18 months. Relapse rates in the two groups were compared using frequency and life-table analysis. Sixty-nine patients with proctitis, 140 with left-sided colitis, and 113 with subtotal or total colitis were evaluated.
  
  
  RESULTS
  In the intention-to-treat analysis, the failure rate (relapses plus withdrawals) was 54.7% in the olsalazine and 47.2% in the sulphasalazine group. In the per-protocol analysis excluding withdrawals, 44.7% relapsed in the olsalazine and 39.3% in the sulphasalazine group. Remission curves did not differ significantly, although at all time intervals the frequency of remission was slightly higher in the sulphasalazine group (p = 0.19 in the intention-to-treat analysis and p = 0.42 in the per-protocol analysis estimated by the log-rank test). Twelve patients (of whom five had diarrhea) in the olsalazine group versus eight patients in the sulphasalazine group discontinued the study because of side effects.
  
  
  CONCLUSIONS
  The relapse-preventing effect of olsalazine and sulphasalazine in sulphasalazine-tolerant patients did not differ. Furthermore, the tolerability of olsalazine, particularly concerning diarrhea, appears to be better than previously reported.
authors.affiliation: Department of Medicine, Umeã Hospitals, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Nilsson
authors.forename: A
authors.initials: A
authors.lastname: Danielsson
authors.forename: R
authors.initials: R
authors.lastname: Löfberg
authors.forename: P
authors.initials: P
authors.lastname: Benno
authors.forename: L
authors.initials: L
authors.lastname: Bergman
authors.forename: O
authors.initials: O
authors.lastname: Fausa
authors.forename: J
authors.initials: J
authors.lastname: Florholmen
authors.forename: A L
authors.initials: AL
authors.lastname: Karvonen
authors.forename: S
authors.initials: S
authors.lastname: Kildebo
authors.forename: B
authors.initials: B
authors.lastname: Kollberg
mesh_terms: D000328:Adult; D000636:Aminosalicylic Acids / Q000009:adverse effects / Q000627:therapeutic use*; D003093:Colitis, Ulcerative / Q000188:drug therapy* / Q000517:prevention & control; D003967:Diarrhea / Q000139:chemically induced; D004311:Double-Blind Method; D005260:Female; D005387:Finland / Q000453:epidemiology; D005500:Follow-Up Studies; D006801:Humans; D015993:Life Tables; D008297:Male; D009664:Norway / Q000453:epidemiology; D012008:Recurrence; D012460:Sulfasalazine / Q000009:adverse effects / Q000627:therapeutic use*; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000636:Aminosalicylic Acids; D012460:Sulfasalazine; C032587:olsalazine