Novel desensitization therapy of mesalamine intolerance in patients with ulcerative colitis

Background: Mesalamine is the first-line drug for treating mild-to-moderate ulcerative colitis (UC); however, some patients develop symptoms of intolerance. Although several desensitization methods have been reported, these desensitization regimens were rather complicated for physicians to prescribe in daily clinical practice; therefore, it has not yet become a major therapeutic option for intolerance patients. Thus, we developed an alternative desensitization protocol.

Methods: We performed a single-center, retrospective study of patients with UC, who were intolerant to mesalamine and had undergone desensitization therapy. Desensitization starts with 50 mg of granule mesalamine, with an increase in the dose by 50 mg every week up to 200 mg, followed by incremental doses of 100 mg every week. After patients received dosages of more than 1000 mg, the dose was increased by 200 mg every week up to the target dose. Concomitant medications such as oral prednisolone or budesonide rectal foam were allowed during the protocol but were withdrawn before the end of desensitization. We evaluated the success rate of our mesalamine desensitization method and performed safety assessments during the protocol.

Results: Of 115 patients, 17 were intolerant to mesalamine. We excluded six patients who had severe disease or organ disorders. Overall, 11 patients received desensitization therapy without hospitalization. All 11 patients successfully underwent desensitization therapy and received the target dose of mesalamine (3000-4000 mg/day) at the end of the protocol. No serious adverse events were observed during this protocol.

Conclusions: This retrospective study reports a successful and safe desensitization method for UC patients with mesalamine intolerance.