title: Azathioprine and mercaptopurine in the management of patients with chronic, active microscopic colitis.
abstract: BACKGROUND
  Microscopic colitis (MC) is a common chronic diarrhoeal disease, and remission can be induced with budesonide. However, diarrhoea relapses frequently when budesonide is tapered and a few patients become budesonide intolerant.
  
  
  OBJECTIVE
  To examine retrospectively the effect of azathioprine (AZA) and mercaptopurine (MP) in patients with chronic, active MC.
  
  
  METHODS
  Data on all MC patients who received AZA or MP in the years 1997-2011 at three centres representing three countries were pooled for analysis. The indications for thiopurine therapy were frequent relapses after short-term treatment (N = 26), budesonide dependency on 6 mg (N = 15) and budesonide intolerance (N = 5). The response to thiopurine treatment was defined as clinical remission, intolerance or nonresponse.
  
  
  RESULTS
  Forty-six MC patients (32 CC and 14 LC), 32 female; median age 59 years (range: 36-83) with a median disease duration of 3 years (range: 0.5-18) were included. Thirteen patients (28%) achieved long-term clinical remission on AZA therapy. AZA failed in 31 patients (67%) due to intolerance and in 2 patients (4%) because of nonresponse. Thirteen of 31 AZA-intolerant patients were switched to MP and 6 patients (46%) obtained clinical remission. Thus, the overall response rate to thiopurines was 19/46 (41%). The main side effects were nausea/vomiting and abnormally elevated liver enzymes.
  
  
  CONCLUSIONS
  In this retrospective case series, the majority of chronic, active MC patients were intolerant to AZA leading to cessation of treatment. However, further studies are needed to explore the efficacy, acceptance, tolerance and safety of MP in patients with chronic, active MC refractory to budesonide.
authors: Division of Gastroenterology and Hepatology, Department of Clinical and Experimental Medicine, Faculty of Health Science, Linköpings University, Linköping, Sweden. andreas.munch@lio.se
authors: A
authors: A
authors: Münch
authors: F
authors: F
authors: Fernandez-Banares
authors: L K
authors: LK
authors: Munck
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000964:Antimetabolites, Antineoplastic / Q000009:adverse effects / Q000627:therapeutic use*; D001379:Azathioprine / Q000009:adverse effects / Q000627:therapeutic use*; D002908:Chronic Disease; D046728:Colitis, Microscopic / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000009:adverse effects / Q000627:therapeutic use*; D008297:Male; D015122:Mercaptopurine / Q000009:adverse effects / Q000627:therapeutic use*; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D000964:Antimetabolites, Antineoplastic; D007166:Immunosuppressive Agents; D015122:Mercaptopurine; D001379:Azathioprine