Azathioprine versus sulfasalazine in maintenance of remission in severe ulcerative colitis.

BACKGROUND: Azathioprine is useful as a steroid-sparing drug in patients with ulcerative colitis. Its role as monotherapy in the maintenance of disease remission has not been evaluated. METHODS: In this prospective, randomized, open-label study, 25 patients with severe ulcerative colitis received either azathioprine (2.5 mg/Kg/day; Group A, n = 12) or sulfasalazine (6 g/day; Group B, n = 13). All patients received oral corticosteroids in a tapering dosage schedule initially. Treatment failure was defined as either disease relapse or drug withdrawal because of adverse effects. RESULTS: Five of 12 patients in Group A and 8 of 13 patients in Group B had sustained remission during the stipulated study period of 18 months (p = ns). Two patients in Group A had to stop azathioprine because of adverse effects (bone marrow suppression and acute pancreatitis). In Group A, all patients who had treatment failure developed it in the first half of the study while in Group B treatment failure occurred in both halves. CONCLUSIONS: The relapse rate of ulcerative colitis on maintenance therapy with azathioprine or sulfasalazine is comparable; there was a trend towards earlier treatment failure with azathioprine.