Sulfasalazine revisited: a meta-analysis of 5-aminosalicylic acid in the treatment of ulcerative colitis.
OBJECTIVE
To assess the effectiveness of the newer 5-aminosalicylic acid (5-ASA) delivery systems compared with placebo or sulfasalazine for the treatment of active ulcerative colitis and for the maintenance of remission.


METHODS
Pertinent studies were selected using the MEDLINE and BIOS (1981 to 1992) data bases, reference lists from published articles, reviews, symposia proceedings, and abstracts from major gastrointestinal meetings.


METHODS
Randomized controlled trials of 5-ASA compared with placebo or sulfasalazine of a minimum of 4 weeks duration for active disease and a minimum of 6 months for maintenance of disease remission. Sixteen trials of 5-ASA for active disease, published either in abstract or full manuscript, were available. Eleven trials of 5-ASA for maintenance of remission were also reviewed.


METHODS
Crude rates for either induction of remission (active disease studies) or maintenance of remission (relapse-prevention trials) based on the intention-to-treat principle were extracted from the studies by two independent observers. Each study was given a quality score, based on predetermined criteria.


RESULTS
Studies were placed in three groups: 5-ASA compared with placebo, 5-ASA compared with sulfasalazine for active disease, and 5-ASA compared with sulfasalazine for maintenance of remission. 5-Aminosalicylic acid was superior to placebo in the treatment of active ulcerative colitis (pooled odds ratio, 2.02; 95% CI, 1.50 to 2.72). A dose-response effect for 5-ASA existed (P < 0.001). For active disease, the pooled odds ratio for 5-ASA compared with sulfasalazine was 1.15 (CI, 0.83 to 1.61). When 5-ASA was compared with sulfasalazine for maintenance of disease remission, the pooled odds ratio was 0.85 (CI, 0.64 to 1.15). Withdrawal rates and reported side effects were similar for 5-ASA compared with placebo- or sulfasalazine-treated patients.


CONCLUSIONS
Although the newer 5-ASA preparations in a dose of at least 2 g/d are more effective than placebo in the treatment of ulcerative colitis, insufficient evidence exists to suggest that they are superior to sulfasalazine. Although they offer a benefit to the sulfasalazine-sensitive patient, use of 5-ASA preparations instead of sulfasalazine in the treatment of ulcerative colitis cannot yet be substantiated.
Sutherland
L R
LR
University of Calgary, Alberta, Canada.
May
G R
GR
Shaffer
E A
EA
D000636:Aminosalicylic Acids / Q000627:therapeutic use*; D003093:Colitis, Ulcerative / Q000188:drug therapy*; D006801:Humans; D019804:Mesalamine; D016017:Odds Ratio; D016032:Randomized Controlled Trials as Topic; D012460:Sulfasalazine / Q000627:therapeutic use*
D000636:Aminosalicylic Acids; D012460:Sulfasalazine; D019804:Mesalamine