The use of thiopurines for the treatment of inflammatory bowel diseases in clinical practice.

Background: Thiopurines are the most commonly used immunomodulatory drugs in inflammatory bowel diseases.
Aim: To evaluate the use, the therapeutic and safety profiles of thiopurines in a large sample of IBD patients.
Methods: We reviewed 3641 case histories of IBD patients. Thiopurines were prescribed in 582 patients (16.0%); the analysis was performed on the 553 (267 ulcerative colitis, 286 Crohn's disease) with exhaustive clinical data.
Results: The main indications for treatment were steroid-dependence (328/553, 59.3%) and steroid-resistance (113/553, 20.7%). Thiopurines were started when CD were younger than UC patients (p<0.001) but earlier from diagnosis in UC than in CD patients (p=0.003). Efficacy was defined as optimal (258/553, 46.6%), partial (108/553, 19.5%), absent (85/553, 15.4%) and not assessable (102/553, 18.4%). Efficacy was independent of disease type, location/extension or duration and age at starting. Side effects were observed in 151/553 (27.3%) patients, leading to drug discontinuation in 101 (18.3%). 15 out of the 130 (11.5%) patients who took thiopurines for more than 4 years relapsed, more frequently in CD than in UC (OR=3.67 95% C.I. 0.98-13.69; p=0.053).
Conclusions: Thiopurines confirm their clinical usefulness and acceptable safety profile in managing complicated IBD patients. The majority of patients treated for longer than 4 years maintain response. No clinical and demographic predictive factors for efficacy and side effects were identified.