Mirabegron Associated Angioedema: A Case Report

Purpose: To review a case of angioedema associated with mirabegron. Summary: A 77-year-old woman presented to the emergency department with swelling of the left anterior side of the tongue beginning 90 minutes prior to arrival. She noticed tingling on her tongue while eating a hamburger, chips, and ice cream. The patient had no history of medication-related allergies. Home medications include acetaminophen, aspirin, biotin, black cohosh, Co-enzyme Q-10, cranberry, fish oil, multivitamin, alendronate, and mirabegron all taken orally. The patient reports being on mirabegron for 3 to 4 years but recently decided to self-taper off the medication. Her initial laboratory test results were unremarkable. The patient was diagnosed with left tongue angioedema, and she received methylprednisolone, epinephrine, famotidine, and 2 units of plasma. After medication administration, the patient underwent a flexible nasopharyngeal laryngoscopy resulting in no significant angioedema in the pharynx and hypopharynx with a small area of possible edema noted on the right base of tongue/lingual tonsil. Patient's symptoms improved with medication treatment and discontinuation of mirabegron. The use of Naranjo et al. adverse-event probability scale revealed that mirabegron was the possible (score of 4) cause of the patient's left tongue angioedema. Conclusion: A 77-year-old woman developed drug induced tongue angioedema associated with mirabegron after being compliant on this medication for 3 to 4 years. Patient was self-tapering her dose of mirabegron. This patient responded well to medication treatment and discontinuation of drug. To our knowledge, this is the second case report of mirabegron induced angioedema.