Coated oral 5-aminosalicylic acid therapy for mildly to moderately active ulcerative colitis. A randomized study.

We assessed oral 5-aminosalicylic acid (5-ASA) prepared with a pH-sensitive polymer coating in 87 patients with mildly to moderately active ulcerative colitis in a double-blind, placebo-controlled trial. Patients were randomly assigned to receive 5-ASA at a dosage of either 4.8 or 1.6 g per day or placebo for six weeks. The outcome was monitored by flexible proctosigmoidoscopic examinations and physicians' assessments at three-week intervals and by patients' recordings of daily symptoms. Results showed 24 percent complete and 50 percent partial responses in those receiving 4.8 g of 5-ASA per day as compared with 5 percent complete and 13 percent partial responses in those receiving placebo (P less than 0.0001, rank-sum test). At a dosage of 1.6 g per day, the response was twice as good as with placebo, but the difference did not reach statistical significance (P = 0.51). Age, sex, duration of disease, duration of active symptoms, or extent of disease did not affect the clinical outcome. We conclude that oral 5-ASA administered in a dosage of 4.8 g per day is effective therapy, at least in the short term, for mildly to moderately active ulcerative colitis.