6-Mercaptopurine or methotrexate added to prednisone induces and maintains remission in steroid-dependent inflammatory bowel disease

Background As treatment of steroid-dependent patients with inflammatory bowel disease (IBD) is controversial, we analysed the efficacy and tolerance of 6-mercaptopurine (6-MP) and methotrexate (MTX) added to prednisone in increasing and maintaining the disease remission rate. Methods Seventy-two steroid-dependent IBD patients, 34 with ulcerative colitis (UC) and 38 with Crohn's disease (CD), receiving treatment with prednisone were randomly assigned in a 2:2:1 ratio to additionally receive, orally, over a period of 30 weeks 1.5 mg/kg/day of 6-MP (group A) or 15 mg/week of MTX (group B), or 3 g/day of 5-aminosalicylic acid (5-ASA) (group C). All patients who achieved remission were included in a maintaining remission study for 76 weeks. Remission was defined after stopping prednisone as a CD activity index of <150 and normal serum orosomucoid concentration for CD patients and a Mayo Clinic score <7 for UC patients. Results With regard to achieved remission, a significantly higher (P < 0.05) rate existed for UC patients in group A (78.6%) than in group C (25%), with no statistical differences in group B (58.3%) versus C. For CD patients, the rates were significantly higher (P < 0.001 and 0.01, respectively) in groups A (93.7%) and B (80%) versus C (14%). With regard to maintaining remission, UC patients in group A (63.6%) presented significantly higher rates (P < 0.0015 and P < 0.007, respectively) versus 14.3% in group B and none in group C. For CD patients, statistical differences (P < 0.001) existed when comparing rates in groups A (53.3%) and B (66.6%) versus none in group C. Noticeable side effects appeared in 13.3% of patients from group A and 11.5% from group B. Conclusions These results suggest that 6-MP or MTX added to prednisone could be effective in steroid sparing, as well as in achieving and maintaining remission in steroid-dependent IBD patients. MTX was less effective in maintaining remission in UC patients. (C) 2000 Lippincott Williams & Wilkins.