title: Thiopurine hepatotoxicity in inflammatory bowel disease: the role for adding allopurinol.
abstract: BACKGROUND
  Immunomodulator therapy with the thiopurine analogues azathioprine or 6-mercaptopurine is commonly prescribed for the treatment of inflammatory bowel disease (IBD). Drug adverse effects and the lack of efficacy, however, commonly require withdrawal of therapy. Allopurinol, a xanthine oxidase inhibitor, was recently evaluated in its role in modifying thiopurine metabolism and improving drug efficacy in IBD.
  
  
  OBJECTIVE
  This article reviews the role and safety of allopurinol co-therapy in the setting of thiopurine hepatotoxicity and/or non-responsiveness in IBD.
  
  
  METHODS
  Published articles on thiopurines in the treatment of IBD were examined.
  
  
  CONCLUSIONS
  The addition of low dose allopurinol to dose-reduced thiopurine analogue seems safe but careful monitoring for adverse effects and profiling of thiopurine metabolites is essential. There is evidence of improved immunomodulator efficacy and reduced hepatotoxicity clinically but further confirmatory studies are required before more definitive treatment recommendations can be given.
authors.affiliation: The University of New South Wales, Bankstown and Concord Hospitals, Gastroenterology and Liver Services, Sydney South West Area Health Service, Sydney, Australia. rupertleong@hotmail.com
authors.forename: Rupert Wl
authors.initials: RW
authors.lastname: Leong
authors.forename: Richard B
authors.initials: RB
authors.lastname: Gearry
authors.forename: Miles P
authors.initials: MP
authors.lastname: Sparrow