A multicenter, randomised, open-label study to evaluate the clinical efficacy and pharmacokinetics of oral tacrolimus (FK506) therapy under fasting and fed conditions in refractory ulcerative colitis

INTERVENTION: Fasting condition group: Tacrolimus ingestion 1 hour before meal Fed condition group: Tacrolimus ingestion immediately following consumption of meal CONDITION: ulcerative colitis PRIMARY OUTCOME: Clinical response (Mayo score) at 2, 12 weeks after treatment. SECONDARY OUTCOME: (1) Mean maximum tacrolimus blood concentration (Cmax), mean time of Cmax (tmax), mean area under the blood concentration‐time curve (AUC), trough level at day1.; (2) Percentage of patients achieved trough tacrolimus whole blood levels between 10 and 15ng/ml within 2 weeks. ; (3) Dose of tacrolimus at 2weeks.; (4) Safety INCLUSION CRITERIA: (1) Patients with refractory (steroid resistance or steroid dependent), moderately active (Mayo score: 6‐10) ulcerative colitis (2) Candidate has to agree to be enrolled for the study under sufficient written informed consent.