Clinical Medicine Reviews in Therapeutics

Tacrolimus, a 23-member macrolide lactone discovered in 1984 from the actinomycete Streptomyces tsukubaensis, was the first macrolide immunosuppressant agent. Tacrolimus was first used for patients after liver transplantation to reduce the activity of the patient's immune system and the risk of organ rejection. Oral tacrolimus was recently approved for use in steroid-refractory moderate-to-severe ulcerative colitis in Japan. This review focuses on the clinical efficacy and safety data of tacrolimus in moderate-to-severe refractory ulcerative colitis.