Metabolic acidosis is a common clinical disturbance due to increased plasma acidity caused by a primary decrease in serum HCO3- concentration. It is classified as normal or high anion gap metabolic acidosis. High anion gap metabolic acidosis can result from either a decrease in unmeasured cations (K+, Ca2+, Mg2+) or an increase in unmeasured anions (PO4 3-, albumin). However, other anions such as lactic acid or keto acids may cause this acid-base disorder. It can also result from renal failure and intoxication (salicylate, methanol, ethylene glycol), or more rarely, from massive rhabdomyolysis and pyroglutamic (5-oxoproline) acidemia. Acidemia due to pyroglutamic acid should be considered when no other aetiology is found. High anion gap metabolic acidosis is diagnosed in children with inherited defects in enzymes of the γ-glutamyl cycle. In adults, this disorder from pyroglutamic acid has been described in association with chronic acetaminophen misuse. We report a case of pyroglutamic acidosis in a woman with acute misuse of acetaminophen concurrent with chronic use.
Learning point: Paracetamol is an easily available drug with potentially harmful consequences.Accumulation of pyroglutamic acid (5-oxoproline) may be a cause of high anion gap metabolic acidosis.Reporting cases of 5-oxoprolinemia acidosis contributes to better understanding of the condition.
Keywords: 5-oxoprolinemia; High anion gap metabolic acidosis; acetaminophen; paracetamol; pyroglutamic acidemia.