Phenazopyridine-Induced Toxicity in an Elderly Patient Receiving a Prolonged Regimen of Therapeutic Doses

Abstract

Phenazopyridine is commonly used for its local analgesic effects on the urinary tract. It is taken with antibiotics for a short time, typically 2 days, to treat dysuria associated with urinary tract infections. Adverse reactions associated with phenazopyridine are limited and include mild gastrointestinal symptoms, headache, and dizziness, but in rare cases, patients can develop severe and life-threatening adverse reactions such as acute renal failure, hemolytic anemia, hepatitis, and methemoglobinemia. 1 We report a case of an elderly patient who developed phenazopyridine-induced toxicity while taking an appropriate dose of phenazopyridine for an extended duration of time.