Methemoglobinemia: A Life-threatening Complication of Topical Pharyngeal Anesthetics.

Drug-induced methemoglobinemia can be caused due to topical anesthetics, dapsone, nitrates (e.g., nitroglycerin), and metoclopramide. Cyanosis in the setting of topical anesthetic use, along with the arterial blood gas results indicating hypoxemia, points towards the diagnosis of methemoglobinemia. We highlight the potential complication with the use of topical pharyngeal benzocaine through this case presentation.