(293) Calcitonin Gene-Related Peptide Inhibitor: Role in Treatment of Hemicrania Continua, with Potential Benefit in Controlling Diarrhea

Abstract

Erenumab is a calcitonin gene-related peptide (CGRP) monoclonal antibody, approved recently for prevention of episodic and chronic migraine. CGRP is involved in the pathogenesis of migraine, and erenumab works by blocking the CGRP receptors. Common side effects include injection site reactions and constipation. Here we present a patient with hemicrania continua (HC) who responded well to erenumab, while the medication additionally treated her debilitating diarrhea. A 61-year-old female with history of intractable, refractory, chronic, daily, left hemicranial headaches with migrainous features associated with restlessness, but without cranial autonomic symptoms, was diagnosed to have HC with 100 % response to high dose indomethacin trial. She was maintained on low dose indomethacin due to severe acid reflux, along with topiramate, and greater occipital nerve cryoanalgesia, with partial relief. The patient had additionally been complaining of chronic daily watery diarrhea of unknown etiology with intolerance to solids and liquids for 1 year prior to staring the indomethacin. She complained of about 6 loose stools per day. The patient was started on erenumab 70 mg subcutaneously and re-evaluated after 4 weeks. She reported 50% improvement in headache frequency and intensity one week after starting the medication, with no side effects. Additionally, four days after erenumab was started she noted that her stools appeared more formed and her bowel movements reduced in frequency to once daily. She denied constipation. We plan to take her off indomethacin if the favorable response continues. CGRP inhibitors are a new class of drugs that appear to show great promise in migraine prophylaxis with minimal side effects. We believe that this case demonstrates potential benefit of erenumab in other headache syndromes such as HC, as well as highlighting its effectiveness in treating diarrhea. Further studies need to be done to ascertain the full potential of these drugs.