Western Journal of Emergency Medicine: Integrating Emergency Care with Population Health

Phenazopyridine is considered one of the classic causes of drug-induced methemoglobinemia. It is often taught as such and seen in board review courses. Nevertheless, the epidemiology is unknown, presentation quite rare, and less than five cases have been reported in PubMed in over 35 years.^1-4 We present a case with a different set of patient characteristics than seen in the few recent case reports, and an approach to treatment that validates further uniqueness, justifying reporting the case in the literature. In particular, the patient was a young otherwise-healthy adult, with the initial diagnosis and decision to treat based on clinical grounds versus laboratory values.