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Copyright ©2008 The WJG Press and Baishideng. All rights reserved.
World J Gastroenterol. Sep 28, 2008; 14(36): 5519-5522
Published online Sep 28, 2008. doi: 10.3748/wjg.14.5519
Are we giving azathioprine too much time?
Fernando Gomollón, Santiago García López
Fernando Gomollón, Department of Digestive Diseases, Clinic University Hospital “Lozano Blesa”, CIBEREHD, IACS, Zaragoza, Spain
Santiago García López, Department of Digestive Diseases, University Hospital “Miguel Servet”, Zaragoza, Spain
Author contributions: Gomollón F and García López S contributed equally to this work.
Correspondence to: Fernando Gomollón, Hospital Clínico Universitario “Lozano Blesa” Zaragoza, Avenida San Juan Bosco 15, Zaragoza 50009, Spain. fgomollon@gmail.com
Telephone: +34-87-6766000 Fax: +34-97-6768846
Received: August 18, 2008
Revised: August 25, 2008
Accepted: September 1, 2008
Published online: September 28, 2008
Abstract

Azathioprine is currently the key drug in the maintenance treatment of inflammatory bowel diseases. However, there are still some practical issues to be resolved: one is how long we must maintain the drug. Given that inflammatory bowel diseases are to date chronic, non-curable conditions, treatment should be indefinite and only the loss of efficacy or the appearance of serious side effects may cause withdrawal. As regards to efficacy and their maintenance over time, evidence supports the continuous usefulness of the drug in the long term: in fact its withdrawal very substantially increases the risk of relapse. About side effects, azathioprine is a relatively well tolerated drug and even indefinite use seems safe. The main theoretical risks of prolonged use would be the myelotoxicity, hepatotoxicity, and the development of cancer. In fact, serious bone marrow suppression or serious liver damage are uncommon, and can be minimized with proper use of the drug. Recent metanalysis suggests that the risk of lymphoma is real, but the individual risk is rather low, and decision analysis suggests a favorable benefit/risk ratio in the long term. Therefore, in patients with inflammatory bowel diseases in whom azathioprine is effective and well tolerated, the drug should not be stopped. This recommendation concerns the use of azathioprine as a single maintenance drug, and is not necessarily applicable to patients receiving concomitant biological therapy.

Keywords: Azathioprine; Inflammatory bowel diseases; Maintenance treatment