Allopurinol-thiopurine combination therapy in inflammatory bowel disease

Author(s): Margien L Seinen, Nanne KH de Boer, Adriaan A van Bodegraven, Stephen B Hanauer & Frank Hoentjen

Combination therapy with allopurinol and low-dose thiopurine (azathioprine and mercaptopurine) has been described as an alternative immunosuppressive strategy in adult inflammatory bowel disease patients. Currently, this combination treatment is used in clinical practice to optimize ineffective or non-tolerated weight-based thiopurine monotherapy. In the setting of persistent disease or thiopurine intolerances in combination with an aberrant (‘skewed’) thiopurine metabolism (6-MMP/6-TGN ≥ 20) allopurinol–thiopurine combination therapy can be a safe and effective approach. Here we will discuss the efficacy and safety of allopurinol–thiopurine combination therapy in inflammatory bowel disease patients. Furthermore, we will review the mechanism of action, recommendations for the use of combination therapy in daily clinical practice and points of interest for future research.