How effective are the usual treatments for ulcerative colitis?

Background: Details of the efficacy of the drugs used in ulcerative colitis are not readily available.
Methods: We have reviewed all placebo-controlled trials of the commonly used drugs for both induction and maintenance of remission to determine the efficacy and to calculate the numbers needed to treat (NNTs) to achieve a specified benefit for each drug.
Results: The drug response rates and the NNTs (with 95% CI) are tabulated for each drug.
Conclusion: Corticosteroids give a remission rate of 68% in mild or moderate disease and an NNT for remission of 2 (95% CI 1.4-5) in mild disease. Intravenous hydrocortisone gives a remission rate of 60-73%. Aminosalicylates are relatively ineffective in inducing remission with an NNT of 10 (95% CI 7-21) improving to 8 (95% CI 5-20) if the dose > or = 3 g daily. They are better at maintenance (NNT = 6; 95% CI 4-8). Intravenous ciclosporin is very effective in achieving remission in severe colitis with an NNT of 1.2 (95% CI 1-2.5). Although there is fairly good evidence that azathioprine is effective in maintaining remission and is used widely, there are no suitable placebo-controlled trials to calculate the NNT.