Metformin toxicity in the intensive care unit: A case series and review of the literature.

Metformin toxicity is a life-threatening condition with high morbidity and mortality. Toxicity predominantly occurs in the setting of acute renal dysfunction, as the drug is solely eliminated by the kidneys. While this risk is widely known to clinicians, diagnosing metformin toxicity is challenging because commercially available serum metformin levels require days to weeks to result.