Objective To explore the ‘real world’ effectiveness of tacrolimus therapy for refractory ulcerative proctocolitis (UC).

Design Retrospective cohort study using prospectively collated clinical data.

Setting A single district general hospital in Kent, UK. Clinical decisions and regular monitoring were undertaken by a single expert in inflammatory bowel disease.

Patients All patients started on tacrolimus between January 2010 and August 2016 at Tunbridge Wells Hospital.

Interventions Following failure of conventional medication, tacrolimus was commenced at 0.5 mg/kg twice daily. Drug trough levels of 5–20 ng/mL were targeted. Other immunomodulation was stopped and steroids were weaned over 4–6 weeks.

Main outcome measures Treatment duration was measured for each patient. If the drug was stopped, the rationale, including specific side effects, was recorded. The patient’s subsequent management plan was noted.

Results Thirty-five patients were started on tacrolimus (range: 18–85, median: 36 years). Disease extent included proctitis to pancolitis. Twenty-five patients derived no benefit. Four patients responded, but drug side effects necessitated withdrawal. Eighteen of these 29 patients (62%) underwent surgery. One patient, who had previously responded, stopped the drug after becoming pregnant (healthy subsequent birth). Therefore, 5 of 35 patients (14%) remain on tacrolimus with sustained clinical response, ranging from 6 to 76 (median: 32) months of treatment. Treatment was most effective for proctosigmoiditis. There were no other demographic or biological markers for success.

Conclusions In line with UK and European guidelines, tacrolimus can be beneficial for refractory UC. With appropriate monitoring, it appears treatment can be continued safely long term.