Review article: maintenance of remission in ulcerative colitis.

Seventy percent of patients with ulcerative colitis can expect to experience a relapse over a 12 month period. Sulfasalazine was the first drug demonstrated to reduce this relapse rate to 21 percent. Subsequent studies have demonstrated that 5-aminosalicylic acid (5-ASA) is the main active component, and preparations containing only 5-ASA have similar efficacy to sulfasalazine. 5-ASA is readily absorbed from the small intestine; to achieve high a colonic lumenal concentration therefore requires special release formulation. A variety of 5-ASA preparations is available, differing in their release mechanism, efficacy and side effect profile. Most patients can be maintained in remission using oral 5-ASA medication. For patients with distal or left sided disease the use of rectal 5-ASA is also of proven benefit in maintaining remission. Some patients with frequent or severe relapses require stronger immunosuppression, and in these patients azathioprine or 6-mercaptopurine (6-MP) are of proven benefit. Azathioprine is also invaluable for maintaining remission in patients who have been treated with cyclosporin for a fulminant acute episode of colitis. The exciting spectre of natural bacterial therapies (probiotics) deserves further exploration.