The use of tacrolimus in the treatment of inflammatory bowel disease.

Tacrolimus is a calcineurin inhibitor that suppresses pro-inflammatory cytokine production and T-cell activation. These immunosuppressant effects have been used to treat inflammatory bowel disease, especially fistulising Crohn's disease and refractory ulcerative colitis. The more predictable oral bioavailability and better side-effect profile makes tacrolimus a more favourable choice as compared with ciclosporin. Dose-dependent side effects, such as nephrotoxicity, are reported but are mostly reversible with dose reduction or cessation of therapy. Topical tacrolimus has also been used to treat pyoderma gangrenosum, an extra-intestinal manifestation of inflammatory bowel disease. Tacrolimus is well-tolerated and should be considered as an alternative agent in the treatment of inflammatory bowel disease, especially those intolerant or refractory to the more conventional immunomodulators.