SAFETY OF AZATHIOPRINE AND 6-MERCAPTOPURINE IN PEDIATRIC-PATIENTS WITH INFLAMMATORY BOWEL-DISEASE

Background & Aims: Azathioprine (AZA) and 6-mercaptopurine (6-MP) are used in pediatric patients with ulcerative colitis and Crohn's disease to reduce disease activity, maintain remission, prevent relapse, and lower corticosteroid dosage, but their long-term side effects remain t o be studied. The aim of this study was to analyze the safety of AZA a nd 6-MP and steroid reduction in this age group. Methods: The investig ators' database identified 118 patients who received either drug; 23 w ere excluded (single visit, noncompliance, or therapy < 1 week), leavi ng 95 patients, with a mean (+/-SD) age of 14.2 +/- 4.4 years. Medical files were reviewed for adverse side effects: fever, pancreatitis, in fections, gastrointestinal intolerance, aminotransferase level increas e, leukopenia, and thrombocytopenia. Prednisone doses before and after immunomodulatory therapy were compared. Results: AZA or 6-MP was tole rated in 51 of 95 patients (54%) without adverse reaction; 27 of 95 (2 8%) experienced side effects that responded to dose reduction 1:23 pat ients) or spontaneously (4 patients), most commonly increased aminotra nsferase level (13.7%). Cessation of therapy was needed in 17 of 95 pa tients (18%), including recurrent fever (4), pancreatitis (4), gastroi ntestinal intolerance (4), and recurrent infections (3). Mean predniso ne dose decreased from 24.3 to 8.6 mg/day. Conclusions: AZA and 6-MP w ere well tolerated in 82% of patients; of these, prednisone reduction occurred in 87%. However, 18% required discontinuation because of hype rsensitivity or infectious side effects.