Thiopurines, either alone or in combination with other medicines, play an important role in the treatment of several gastrointestinal and hepatological diseases. Thiopurines have demonstrated their utility as steroid sparing medications for the maintenance of remission in inflammatory bowel disease and autoimmune hepatitis, and they may be explored for avoiding postoperative Crohn disease recurrence if there is a moderate chance of this occurring. When used with infliximab treatment, they decrease antibody development while increasing biologic drug levels. Thiopurines’ normal clinical usage, however, has been called into doubt due to a variety of possible side effects.

The purpose of this article is to give information about the use, and especially the safety, of these drugs in clinical practice in light of such potentially serious, albeit infrequent, side effects.