Background: Recent evidence indicates that intravenous or oral therapy with tacrolimus (FK-506) is effective in treating patients with Crohn's disease. We evaluated the usefulness of tacrolimus therapy for Japanese patients with refractory Crohn's disease.
Methods: Fourteen adult Japanese patients with Crohn's disease that was refractory to conventional therapies, including prednisolone (n = 5), azathioprine (n = 6), and infliximab (n = 5), were enrolled. Treatment with tacrolimus was started orally or intravenously and aimed for serum trough levels of 10-15 ng/ml. After the patients achieved clinical improvement, tacrolimus maintenance therapy was administered to maintain the trough level at 5-10 ng/ml.
Results: All patients achieved remission or significant improvement 40 days after starting tacrolimus treatment. By 120 days after the start of therapy, 9 (64%) patients achieved remission, 2 patients (14%) achieved significant improvement, and only 3 patients (21%) relapsed. The relapsed patients were treated with infliximab therapy and achieved remission. Steroids were discontinued by the 5 patients who had taken steroids before the study began. Adverse effects of tacrolimus included a temporary increase in serum creatinine concentration (n = 1, 7%), hyperkalemia (n = 1, 7%), and tremor (n = 1, 7%).
Conclusions: Tacrolimus therapy is effective and well tolerated in patients with Crohn's disease that is refractory to conventional therapies.