The use of traditional and newer calcineurin inhibitors in inflammatory bowel disease

Background: Intravenous cyclosporine A (CsA) is an effective treatment for patients with severe, steroid-refractory ulcerative colitis (UC). Like the response to CsA, clinical trials have shown that two-thirds of patients with refractory UC respond to tacrolimus therapy. However, it is unclear how/when this agent should be used for patients with active UC. Methods: We reviewed the results of previous studies regarding calcineurin inhibitors in UC patients. We examined the best way to use tacrolimus to obtain maximum efficacy by comparing the results from clinical trials with those from a recent survey in Japan. Results: Calcineurin inhibitors are useful to induce remission in patients with refractory UC; however, the long-term prognosis has not been shown to be improved by CsA. Early intervention with CsA/tacrolimus may improve the long-term prognosis of UC patients just as infliximab does for Crohn's disease patients. Recent studies have indicated that a fasting state and administration of a higher dosage of tacrolimus at the beginning of therapy are critical in ensuring that the target trough concentration of the agent is reached. Conclusions: The use of higher initial doses of tacrolimus ensured that patients achieved their target levels. Further studies will be needed to elucidate the efficacy of top-down therapy with tacrolimus in patients with UC. Physicians must know how to use calcineurin inhibitors to obtain maximum efficacy.