Controlled trial of azathioprine in chronic ulcerative colitis.

A double-blind controlled trial of azathioprine in a dose of 2-2.5 mg/kg body weight over six months was conducted among 44 patients with active chronic ulcerative colitis. Three patients treated with placebo did not complete the trial because their disease became so severe that colectomy was performed. Among patients who completed the trial the mean dose of prednisolone necessary to control the disease decreased in those treated with azathioprine and those treated with placebo; the reduction was greater among those who took azathioprine (p less than 0.001). Activity of the disease apparently improved in both treatment groups but a significant (p less than 0.001) trend was observed only in those patients treated with azathioprine. No serious side effects from azathioprine occurred during the trial but seven of 24 patients had to stop the drug because of nausea. Azathioprine may have a role in the treatment of a few patients wih troublesome chronic colitis for whom conventional drug treatment is ineffectual, or for whom continuous systemic corticosteroid treatment is needed to control symptoms, and for whom surgical treatment is inappropriate.