Objective The calcineurin inhibitor tacrolimus has been shown to be safe and effective as salvage therapy for steroid-refractory ulcerative colitis (UC). Since differences in the onset of action between various agents are thought to influence the achievement and maintenance of disease remission, top-down or accelerated step-up therapy with tacrolimus may be useful. However, the efficacy of tacrolimus in moderate to severe UC patients not receiving concomitant steroids remains unknown.
Methods Ten patients (11 attacks) with active, moderate to severe UC were treated with oral tacrolimus at a dose of 0.1 mg/kg body weight daily. The dosages were adapted to maintain trough whole-blood levels of 10 to 15 ng/mL to induce remission and 5 to 10 ng/mL to maintain remission. Lichtiger scores, the incidence of adverse effects (serum creatinine and glucose) and long-term outcomes were assessed.
Results At four weeks after the initiation of tacrolimus therapy, clinical remissions were observed for eight attacks (72.7%) and clinical responses were demonstrated for three attacks. At 12 weeks after the initiation of tacrolimus treatment, clinical remissions were achieved for nine attacks (90%). After a mean follow-up of 10.4 months, clinical remissions were maintained for eight of 11 attacks. During the tacrolimus treatment, the serum creatinine and glucose levels were not significantly elevated.
Conclusion Oral tacrolimus is a safe and effective therapy for the treatment of moderate to severe UC in patients not receiving concomitant treatment with systemic steroids. Although further studies are required to establish the efficacy and safety of oral tacrolimus therapy in patients with UC, oral tacrolimus may represent a top-down or accelerated step-up treatment option for patients with moderate to severe UC.