Is there a role for thioguanine therapy in IBD in 2017 and beyond?

ABSTRACT

Introduction: Conventional thiopurines are effective for the maintenance of remission of Crohn’s disease and ulcerative colitis, however, up to half of patients are intolerant or unresponsive to these medications. Thioguanine is an alternative thiopurine that has shown efficacy in inflammatory bowel disease, and is particularly useful to circumvent certain side effects associated with conventional thiopurines, for example, pancreatitis. Its association with nodular regenerative hyperplasia of the liver has hindered its widespread use.

Areas covered: We aim to outline the rational use of thioguanine, including safety monitoring, with particular regard to hepatotoxicity. A literature search was performed: PubMed was searched for full papers and abstracts published in English since January 2000 using the following terms, alone and in combination: ‘azathioprine’, ‘thiopurine’, ‘Crohn’s disease’, ‘inflammatory bowel disease’, ‘nodular regenerative hyperplasia’, ‘mercaptopurine’, ‘thioguanine’, ‘ulcerative colitis’. Further relevant papers were identified from the reference lists of selected papers.

Expert commentary: Despite optimisation strategies such as metabolite measurements and the use of allopurinol, a significant proportion of patients will remain intolerant to thiopurines, especially those with allergic reactions, including pancreatitis. For this subgroup of patients we suggest that low dose thioguanine is an alternative to other therapies that are either parenteral or expensive.

KEYWORDS:

• Azathioprine
• conventional thiopurines
• crohn’s disease
• inflammatory bowel disease
• nodular regenerative hyperplasia
• mercaptopurine
• thioguanine
• ulcerative colitis

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Additional information

Funding

This paper was not funded.