title: Methemoglobinemia and acute hemolysis after tetracaine lozenge use.
abstract: Acquired methemoglobinemia is a rare but severe condition associated with oxidizing stressors, most notably medications. Although the symptoms can be life threatening, they usually respond promptly to exposure cessation and methylene blue injection. We describe the first case of methemoglobinemia associated with tetracaine lozenge use. A previously healthy 33-year-old man was admitted with fever, respiratory distress, cyanosis, and acute hemolysis. Physical findings and chest radiograph were normal. Low pulse oximetry readings contrasted with normal partial pressure of oxygen and calculated oxygen saturation. The methemoglobin level was 10.8%. The patient recovered with methylene blue injection and blood transfusions. He reported recent self-medication with tetracaine lozenges for a sore throat during a flu-like illness. No other cause of methemoglobinemia was found.
authors.affiliation: Service de Réanimation Médicale, Hôpital Saint Louis, Assistance Publique des Hôpitaux de Paris, 75475 Paris Cedex 10, France.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Lavergne
authors.forename: Michael
authors.initials: M
authors.lastname: Darmon
authors.forename: Vincent
authors.initials: V
authors.lastname: Levy
authors.forename: Elie
authors.initials: E
authors.lastname: Azoulay
mesh_terms: D000208:Acute Disease; D000284:Administration, Oral; D000328:Adult; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000009:adverse effects*; D003937:Diagnosis, Differential; D006461:Hemolysis; D006801:Humans; D008297:Male; D008708:Methemoglobinemia / Q000139:chemically induced*; D013748:Tetracaine / Q000008:administration & dosage / Q000009:adverse effects*
chemical_list: D000779:Anesthetics, Local; D013748:Tetracaine