Objective: We and others have reported the use of tacrolimus in refractory inflammatory bowel disease (IBD). Little is known about its long-term efficacy and safety.
Methods: In this retrospective, observational single center study the charts of 53 adult patients with steroid-dependent (n = 18) or steroid-refractory (n = 35) IBD, Crohn's disease (CD) (n = 11), ulcerative colitis (UC) (n = 40), or pouchitis (PC) (n = 2) were reviewed. Tacrolimus (0.1 mg/kg body weight per day) was administered orally in all and initially intravenously in 2 patients (0.01 mg/kg body weight per day), aiming for serum trough levels of 4-8 ng/mL. Forty-one of 53 (77.1%) patients were receiving concomitant azathioprine. The mean treatment duration was 25.2 +/- 4.6 SD months (0.43-164 months). Patients were followed for a mean of 39 +/- 4.1 SD months (5-164 months). Response was evaluated using a modified clinical activity index (M-CAI).
Results: Thirty-one UC (78%), 10 CD (90.1%), and both PC (100%) patients experienced an immediate clinical response or went into remission at 30 days. A statistically significant drop on the M-CAI was documented for UC and CD patients. Nine UC patients (22.5%) underwent colectomy between 1.6 and 41.3 months following initiation. Mean colectomy-free survival was 104.8 +/- 15.5 (95% CI 74.4-135.2) months (limited to 164.4 months). Cumulative colectomy-free survival was estimated 56.5% at 43.8 months. Steroids were reduced or discontinued in 40 of 45 UC and CD patients (90%) taking steroids. Side effects included a temporary rise of creatinine (n = 4, 7.6%), tremor or paresthesias (n = 5, 9.4%), hyperkalemia (n = 1, 1.9%), hypertension (n = 1, 1.9%), and opportunistic infections (n = 2, 3.8%).
Conclusion: Long-term tacrolimus therapy appears safe and effective in refractory IBD.