Tacrolimus (FK506) for induction of remission in refractory ulcerative colitis Audio summaries | Evidence Aid summaries | Cochrane Methodology abstracts One study that tested the effectiveness of tacrolimus as therapy for treatment resistant ulcerative colitis was reviewed. Ulcerative colitis is a relapsing inflammatory disease restricted to the colon. Symptoms include bloody diarrhea, passage of pus and/or mucus and abdominal cramping during bowel movements. Tacrolimus is an immunosuppressant that may inhibit transcription of the interleukin 2 gene required for T cell activation thereby suppressing the inflammation associated with ulcerative colitis. The study compared two dosing regimens of tacrolimus (high serum concentration and low serum concentration) with placebo (inactive pill) and found that tacrolimus was effective for improving the symptoms of ulcerative colitis at two weeks. No benefit for induction of remission was noted. Patients in the high serum concentration group were significantly more likely than placebo patients to experience side effects related to treatment. Most of the side effects that occurred during the study were mild and included finger tremor, sleepiness, hot flush, headache, queasiness, stomach discomfort, hypomagnesemia and kidney problems. Two patients developed serious side effects during the study. One patient in the high serum concentration group developed serious viral gastroenteritis.
