Effect of acute paracetamol overdose on changes in serum and urine electrolytes

Br J Clin Pharmacol. 2007 Dec;64(6):824-32. doi: 10.1111/j.1365-2125.2007.02952.x. Epub 2007 Jul 4.


Aims: To investigate the effects of acute paracetamol overdose on renal function, serum and urine electrolyte excretion in man.

Methods: Two studies were performed in patients admitted with paracetamol overdose: a retrospective study examining changes in serum electrolytes, and a prospective study evaluating changes in serum and urine electrolytes. A control group with SSRI overdose was included in the prospective study.

Results: There was a significant dose-dependent relationship between admission (4 h) paracetamol concentration and fall in serum potassium in the retrospective study (P < 0.01) and a significant positive relationship between serum paracetamol at 4 h and fractional excretion of potassium at 12 h postingestion (P < 0.01) in the prospective study. No changes were seen in the control group. No cases developed renal failure.

Conclusions: Paracetamol overdose is associated with dose-related hypokalaemia, and kaliuresis of short duration (<24 h), suggesting a specific renal effect of paracetamol in overdose perhaps via cyclo-oxygenase inhibition. This effect seems distinct from any nephrotoxic effect of paracetamol.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetaminophen / blood
  • Acetaminophen / poisoning*
  • Acetaminophen / urine
  • Adolescent
  • Adult
  • Drug Overdose
  • Electrolytes / blood*
  • Electrolytes / urine*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Prospective Studies
  • Retrospective Studies


  • Electrolytes
  • Acetaminophen