Background: Details of the efficacy of the various drugs used in Crohn's disease are not readily available.
Methods: We have reviewed all placebo controlled trials of the commonly used drugs in Crohn's disease for both the 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: Both the drug response rates and the NNTs (with 95% confidence intervals) are tabulated for each drug.
Conclusion: Prednisolone/prednisone is the most effective drug to achieve remission with a remission rate of 60% and an NNT for remission of 3 (95% confidence interval: 2-6). Aminosalicylates are only moderately effective in achieving remission with an overall NNT of 10 (95% confidence interval: 6-75), but more effective in high-dose (e.g. NNT for Pentasa 4 g daily = 4; 95% confidence interval: 2.6-9), and less effective in maintaining remission with an NNT of 14 (95% confidence interval: 9-29). Both azathioprine and infliximab are associated with remission induction and maintenance rates of 40-66% and NNTs of 3-5. Methotrexate intramuscularly has a remission induction rate of 39% and an NNT of 5 (95% confidence interval: 3-25).