SHM Converge Scientific Abstract ePoster Gallery-A Case of Hemolytic Anemia and Methemoglobinemia Following Phenazopyridine Use

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This case report describes an 80-year-old man who presented to the emergency department after a brief syncopal episode. He had recently been prescribed phenazopyridine for a urinary tract infection 10 days earlier. On examination, he had scleral icterus and generalized jaundice. Initial workup ruled out stroke, but laboratory studies showed severe anemia (hemoglobin 6.8 g/dL), elevated reticulocytes, indirect hyperbilirubinemia, acute kidney injury, elevated LDH, low haptoglobin, a negative Coombs test, and an elevated methemoglobin level. Peripheral smear revealed bite cells, suggesting oxidative hemolysis.<br /><br />Because of suspicion for a hemolytic process, glucose-6-phosphate dehydrogenase (G6PD) testing was performed and showed markedly low enzyme activity, confirming acute hemolytic anemia due to G6PD deficiency. The patient was treated with a blood transfusion and intravenous fluids, with clinical improvement over three days. He was discharged with counseling to avoid phenazopyridine and other oxidant medications.<br /><br />The report emphasizes that phenazopyridine can trigger hemolysis in patients with G6PD deficiency and may also cause methemoglobinemia. Although this association is known, reported cases are rare. The authors note that G6PD deficiency is globally distributed, with higher prevalence in certain populations, and that drug-induced hemolysis can be associated with serious complications including cyanosis, seizures, arrhythmias, and death. They also highlight an important diagnostic pitfall: G6PD levels can appear falsely normal during acute hemolysis, so testing is often recommended after recovery.

Asset Subtitle

Omair Khan

Meta Tag

Author List Arafat Farooqui, Armando Seitllari, Chanaka Seneviratne, Christiana Atuaka, Jude Tabba, Omair Khan, Sanjay Maheshwari, Sime Maharaj, Syed Mohammad Mazhar Uddin, Thi Ha Zaw

Category Clinical Vignettes

Concept Phenazopyridine

Concept Hemolytic Anemia

Concept Glucose-6-Phosphate Dehydrogenase Deficiency

Concept Drug-Induced Hemolysis

Concept Methemoglobinemia

Distinguished Non-Finalist

Presenter Organization Maimonides Medical Center

Presenting Author Omair Khan

Track Adult

Keywords

phenazopyridine

G6PD deficiency

acute hemolytic anemia

methemoglobinemia

oxidative hemolysis

bite cells

indirect hyperbilirubinemia

Coombs negative

acute kidney injury

drug-induced hemolysis

Phenazopyridine

Hemolytic Anemia

Glucose-6-Phosphate Dehydrogenase Deficiency

Drug-Induced Hemolysis

Methemoglobinemia