Beneficial and Harmful Effects of Azathioprine and Allopurinol Versus Standard Azathioprine Therapy for Patients With Ulcerative Colitis

Azathioprine is considered first line immunomodulatory therapy for patients with ulcerative colitis. Up to 50% are treatment failures or experience adverse events leading to treatment withdrawal. Recent evidence suggests that the combination of allopurinol and low dose azathioprine increases the proportion of treatment responders and reduce the risk of adverse events. Objectives: To evaluate the beneficial and harmful effects of low dose azathioprine and allopurinol versus standard azathioprine monotherapy in patients with ulcerative colitis.