Nicorandil and idiopathic anal ulceration

Several reports have implicated nicorandil as a reversible cause of anal ulceration. We have recently commenced a specialist clinic for patients presenting with severe anal ulceration to assess treatment in this difficult group. Recognition of this association may avoid unnecessary surgery.

Twenty-six patients treated with nicorandil had severe painful anal ulceration. Examination under anesthesia was required to biopsy the lesions to exclude neoplasia or inflammatory bowel disease. In total, three patients had proximal diverting stomas without subsequent ulcer resolution, two had perineal debridement with one requiring subsequent skin grafting, and one had an abdominoperineal excision for unremitting pain.

The association of perianal ulceration with nicorandil became apparent only in the latter part of this series. Ten ulcers successfully re-epithelialized when nicorandil was stopped. Nine patients reported anal pain relief and partial healing on clinical examination at two months but failed to show subsequent complete resolution. One patient agreed to nicorandil cessation and reported symptomatic anal pain relief at two weeks but subsequently developed unstable angina requiring hospital admission. Nicorandil was recommenced with anal pain relapse.

Failure to recognize nicorandil as an etiologic factor in the development of anal ulceration, when other potential underlying well-recognized inflammatory or neoplastic processes have been excluded, may lead to unnecessary surgical intervention in a group of high-risk patients. One of our patients had a potentially avoidable abdominoperineal resection. Pharmaceutical manipulation with alternative antiangina medication may induce healing. Pharmacologic manipulation should be coordinated with a physician to minimize precipitation of unstable angina.