Maintenance azathoprine in Crohn’s disease: how long? ▸

Thiopurine therapy is known to be an effective maintenance therapy in Crohn’s disease. In patients who enter prolonged remission, there is concern about long term therapy because of the potential for bone marrow suppression, opportunistic infection, and the possibility of an increased risk of malignancy, particularly lymphoma. The benefit of continuing therapy has been addressed in this study, from 11 centres, in a double blind withdrawal trial. Patients in remission for more than 3.5 years (mean five years) either continued azathioprine at a mean dose of 1.7 mg/kg (n = 40) or switched to placebo (n = 43) for 18 months. Most of these patients had colonic disease (with or without small bowel involvement). During this time, 3/40 (8%) relapsed in the azathioprine group and 9/43 (21%) on placebo. The difference was 13.4% and the upper limit of the 95% confidence limit for this difference was 26%. The trial was powered to test for non-inferiority of the placebo …