title: Systematic review: short-term adverse effects of 5-aminosalicylic acid agents in the treatment of ulcerative colitis.
abstract: OBJECTIVE
  To determine whether there is a difference in short-term adverse events in patients with ulcerative colitis treated with mesalazine, olsalazine or balsalazide.
  
  
  METHODS
  MEDLINE was searched for articles published until 2002. Randomized trials of oral mesalazine, olsalazine or balsalazide for the treatment of active disease or the maintenance of remission were included. Outcomes of interest were the frequencies of patients experiencing adverse events and those withdrawn due to adverse events.
  
  
  RESULTS
  Forty-six trials were included. One study of mesalazine vs. sulfasalazine for active colitis showed significantly fewer patients with adverse events with mesalazine. Both balsalazide vs. sulfasalazine studies for active disease showed significantly fewer withdrawals with balsalazide. One trial of balsalazide vs. sulfasalazine for maintenance showed significantly fewer patients with adverse events with balsalazide. Otherwise, no significant differences in safety outcomes were noted.
  
  
  CONCLUSIONS
  All three 5-aminosalicylic acid agents are safe in the short term. In mesalazine-treated patients, the frequencies of adverse events or withdrawals due to adverse events were comparable with those in placebo-treated patients and lower than those in sulfasalazine-treated patients. Overall, adverse events or withdrawals were not significantly more frequent with olsalazine than with placebo or sulfasalazine. Adverse events and study withdrawals on balsalazide were less frequent than those on sulfasalazine.
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55905, USA. loftus.edward@mayo.edu
authors.forename: E V
authors.initials: EV
authors.lastname: Loftus
authors.forename: S V
authors.initials: SV
authors.lastname: Kane
authors.forename: D
authors.initials: D
authors.lastname: Bjorkman
mesh_terms: D000284:Administration, Oral; D000636:Aminosalicylic Acids / Q000008:administration & dosage / Q000009:adverse effects; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000009:adverse effects*; D000897:Anti-Ulcer Agents / Q000008:administration & dosage / Q000009:adverse effects; D003093:Colitis, Ulcerative / Q000188:drug therapy*; D004311:Double-Blind Method; D006801:Humans; D019804:Mesalamine / Q000008:administration & dosage / Q000009:adverse effects*; D010659:Phenylhydrazines; D016032:Randomized Controlled Trials as Topic
chemical_list: D000636:Aminosalicylic Acids; D000894:Anti-Inflammatory Agents, Non-Steroidal; D000897:Anti-Ulcer Agents; D010659:Phenylhydrazines; D019804:Mesalamine; C038637:balsalazide; C032587:olsalazine