A 65-year-old man with chronic migraine was started on propranolol, followed by monthly erenumab injections (70 mg). His monthly migraine days (MMDs), previously 10 days with frequent triptan use, were reduced after 3 months. Following the 23rd injection, the patient developed lower-right abdominal pain. Imaging revealed a paralytic ileus without obstruction (Picture 1, 2). He had no history of abdominal surgery, relevant medications, or inflammatory disease based on the CRP levels. Significant atherosclerosis was observed but was excluded as a cause. The symptoms improved with conservative treatment and erenumab discontinuation, with no recurrence of MMDs, abdominal pain, or constipation. Constipation is a common erenumab side effect and is managed with laxatives. Food and Drug Administration safety alerts highlight rare but serious complications, including intestinal obstruction and ileus (1). Paralytic ileus after abdominal surgery under erenumab administration suggests an association with calcitonin gene-related peptide receptor blockade (2). Continuous monitoring of abdominal symptoms via symptom checks and diagnostic tests is recommended for long-term erenumab use, particularly in elderly patients.
Picture 1.
Picture 2.
Author’s disclosure of potential Conflicts of Interest (COI).
Shoji Kikui: Speaking fees, Amgen, Daiichi Sankyo, Eli Lilly, and Otsuka Pharmaceutical. Danno Daisuke: Speaking fees, Amgen, Daiichi Sankyo, Eli Lilly, and Otsuka Pharmaceutical. Takao Takeshima: Speaking fees, Amgen, Daiichi Sankyo, Eisai, Eli Lilly, Otsuka Pharmaceutical; Editorial boards, the Japanese Headache Society, and the Japanese Society for Neurology.
Acknowledgments
We thank Sarah Williams, PhD, for editing this manuscript.
References
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