Acute renal failure due to phenazopyridine (Pyridium®) overdose: case report and review of the literature

Abstract

Phenazopyridine (Pyridium) is a commonly used urinary tract analgesic. It has been associated with yellow skin discoloration, hemolytic anemia, methemoglobinemia, and acute renal failure, especially in patients with preexisting kidney disease. We report a 17-year-old female with vertically transmitted human immunodeficiency virus (HIV) infection, presenting with acute renal failure and methemoglobinemia following a suicidal attempt with a single 1,200 mg ingestion of Pyridium. She had no prior evidence of HIV nephropathy. The patient had a progressive nonoliguric renal failure on the 3rd day following the ingestion. She was treated with N-acetylcysteine, intravenous carnitine, and alkalinization of the urine. Her kidney biopsy revealed acute tubular necrosis with no glomerular changes. After 7 days of conservative management, she was discharged home with normal kidney function. To our knowledge, this is the second smallest amount of Pyridium overdose resulting in acute renal failure with no previous history of kidney disease.

Phenazopyridine abuse presenting with acute kidney injury, hemolytic anaemia and jaundice

“…The majority of the parent drug and its toxic metabolites; p-aminophenol, N-acetyl-p-aminophenol, aniline, tri-aminopyridine are excreted. Excretion is impaired in renal dysfunction [3][4][5][6]. Side-effects include orange discoloration of urine, yellowish discoloration of skin, diarrhoea, hepatitis, hemolytic anaemia, methemoglobinemia and acute renal dysfunction [2].…”

Phenazopyridine associated acute interstitial nephritis and review of literature

“…[2][3][4][5] Phenazopyridine associated acute renal failure and AIN are rare but recognizable phenomena with phenazopyridine use in patients with renal dysfunction. 6,7 Few case reports have highlighted renal failure due to phenazopyridine overdose in patients with normal renal function [3][4][5][8][9][10][11][12][13][14][15][16][17][18] (Table 1). Various mechanisms have been postulated for phenazopyridine causing acute renal failure.…”

“…[1][2][3] Secondly, phenazopyridine also causes acute hemolytic anemia, especially in patients with renal insufficiency leading to tubular damage. 4,8 Thirdly, phenazopyridine overdose can cause methemoglobinemia, which leads to hypoxic injury to medullary and papillary segments. In rat models, phenazopyridine-induced methemoglobinemia has shown to cause interstitial edema, cast formation, tubular degeneration and regeneration.…”

Acute Renal Failure and Jaundice without Methemoglobinemia in a Patient with Phenazopyridine Overdose: Case Report and Review of the Literature

“…Its use is associated with gastrointestinal discomfort and orange discoloration of urine [2]. Rarely, patients have developed pigment stones due to the red azo dye which is part of the drug's formulation [1].…”

“…Rarely, patients have developed pigment stones due to the red azo dye which is part of the drug's formulation [1]. In large doses, phenazopyridine has been reported to cause renal failure, methemoglobinemia, skin pigmentation, and hemolytic anemia [2–7]. These findings often occur together, although isolated renal failure has been reported in pediatric patients and in patients with underlying renal disease [4, 7, 8].…”