title: Benzocaine-induced methemoglobinemia in two patients: interdisciplinary collaboration, management, and near misses.
abstract: Methemoglobin, a form of hemoglobin that does not bind oxygen, is produced when iron in red blood cells is oxidized from the ferrous state to the ferric state. Methemoglobinemia develops in the presence of oxidizing agents, such as benzocaine-containing topical anesthetic sprays, and it is characterized by cyanosis. If untreated, methemoglobinemia may prove lethal. We describe two patients who developed methemoglobinemia after they were administered benzocaine-containing topical anesthetic sprays. Using the Naranjo adverse drug reaction probability scale, the relationship between the administration of the benzocaine-containing spray and the development of methemoglobinemia was probable (score of 7) in both patients. Collaboration among health care providers is necessary to efficiently recognize, treat, and manage this condition.
authors.affiliation: Department of Pharmacy Practice, Midwestern University College of Pharmacy-Glendale, Glendale, Arizona 85803, USA. mthrom@midwestern.edu
authors.forename: Melinda J
authors.initials: MJ
authors.lastname: Throm
authors.forename: Margie Dale
authors.initials: MD
authors.lastname: Stevens
authors.forename: Carol
authors.initials: C
authors.lastname: Hansen
mesh_terms: D000287:Administration, Topical; D000328:Adult; D000336:Aerosols; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000009:adverse effects*; D001566:Benzocaine / Q000008:administration & dosage / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007400:Interprofessional Relations; D008297:Male; D008708:Methemoglobinemia / Q000139:chemically induced* / Q000175:diagnosis / Q000503:physiopathology; D008875:Middle Aged; D010348:Patient Care Team
chemical_list: D000336:Aerosols; D000779:Anesthetics, Local; D001566:Benzocaine