UMEM Educational Pearls

Category: Toxicology

Title: Metformin Toxicity - An Emergency Department Diagnosis

Keywords: lactic acidosis, metformin, renal failure (PubMed Search)

Posted: 7/10/2008 by Fermin Barrueto, MD (Updated: 4/24/2024)
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  • Metformin is the most commonly prescribed oral diabetic mediction in US
  • Relative contraindication is in renally impaired patients, they are susceptible to the lactic acidosis
  • Lethal adverse effect is the increase production of lactate
  • ED patient with an anion gap metabolic acidosis, check for metformin and check the lactate
  • The lactic acidosis is often severe (>10 mmol/L) and carries a high mortality rate that has been estimated at >40%
  • Correction of pH and emergent hemodialysis are essential


Perrone et al. Occult metformin Toxicity in Three patients with profound lactic acidosis. J Emerg Med 2008, June 18.