title: Troponin leak associated with drug-induced methemoglobinemia.
abstract: Drug-induced methemoglobinemia is a well-described entity but has not been previously associated with elevated troponins in the absence of cardiac symptoms. We report a case of a patient presenting to the emergency department (ED) with complaints related to an exacerbation of her long-standing cystitis. A low pulse oximetry reading prompted an evaluation, revealing a troponin leak, which peaked at 10 hours. Her methemoglobin level was found to be elevated at 11.4%, but a preexisting anemia apparently prevented the clinical recognition of cyanosis. The methemoglobinemia was determined to be secondary to her ingestion of phenazopyridine and trimethoprim-sulfa methoxizole. Although phenazopyridine and sulfa agents have long been known to cause methemoglobinemia, our patient exhibited an asymptomatic troponin leak that has not been previously reported as a complication of drug-induced methemoglobinemia. Clinicians should be aware of this potential association.
authors.affiliation: Department of Emergency Medicine, Lehigh Valley Hospital and Health Network, 1240 South Cedar Crest Boulevard, Allentown, PA 18103.
authors.forename: Robert D
authors.initials: RD
authors.lastname: Cannon
authors.affiliation: Department of Emergency Medicine, Lehigh Valley Hospital and Health Network, 1240 South Cedar Crest Boulevard, Allentown, PA 18103.
authors.forename: Michael
authors.initials: M
authors.lastname: Wagner
authors.affiliation: Department of Emergency Medicine, Lehigh Valley Hospital and Health Network, 1240 South Cedar Crest Boulevard, Allentown, PA 18103. Electronic address: jeannejacoby38@yahoo.com.
authors.forename: Jeanne L
authors.initials: JL
authors.lastname: Jacoby
mesh_terms: D000779:Anesthetics, Local / Q000009:adverse effects*; D000892:Anti-Infective Agents, Urinary / Q000009:adverse effects*; D018856:Cystitis, Interstitial / Q000188:drug therapy*; D005260:Female; D006801:Humans; D008708:Methemoglobinemia / Q000097:blood / Q000139:chemically induced* / Q000150:complications; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000097:blood* / Q000209:etiology; D010621:Phenazopyridine / Q000009:adverse effects*; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000009:adverse effects*; D019210:Troponin I / Q000097:blood*
chemical_list: D000779:Anesthetics, Local; D000892:Anti-Infective Agents, Urinary; D019210:Troponin I; D015662:Trimethoprim, Sulfamethoxazole Drug Combination; D010621:Phenazopyridine