Guilty as charged: unmeasured urinary anions in a case of pyroglutamic acidosis

Neth J Med. 2008 Sep;66(8):351-3.


A patient developed an unexplained metabolic acidosis with the characteristics of renal tubular acidosis. By correcting the serum anion gap for hypoalbuminaemia and analysing the urinary anions and cations, the presence of unmeasured anions was revealed. The diagnosis of pyroglutamic acidosis, caused by a combination of flucloxacillin and acetaminophen, was established. Strategies for solving complex cases of metabolic acidosis are discussed.

Publication types

  • Case Reports

MeSH terms

  • Acetaminophen / adverse effects
  • Acid-Base Equilibrium
  • Acidosis / chemically induced
  • Acidosis / diagnosis
  • Acidosis / physiopathology*
  • Acidosis / urine
  • Aged
  • Anions
  • Anti-Bacterial Agents / adverse effects
  • Cations
  • Female
  • Floxacillin / adverse effects
  • Humans
  • Pyrrolidonecarboxylic Acid / blood*
  • Risk Factors


  • Anions
  • Anti-Bacterial Agents
  • Cations
  • Acetaminophen
  • Floxacillin
  • Pyrrolidonecarboxylic Acid