title: Metformin overdose-induced hypoglycemia in the absence of other antidiabetic drugs.
abstract: BACKGROUND
  Lactic acidosis is a well-recognized consequence of metformin. Hypoglycemia has been reported previously in metformin overdose, but the presence of other co-ingestions (e.g., a sulfonylurea) was not definitively excluded.
  
  
  METHODS
  A 15-year-old girl ingested 75 g of metformin and 3 g of quetiapine. On examination in the emergency department 2 h later, she was drowsy but had normal vital signs. She developed lactic acidosis, hypotension, and recurrent and severe hypoglycemia (15 mg/dL and 20 mg/dL), requiring boluses of 50%dextrose. The first episode of hypoglycemia occurred approximately 4 h after ingestion. Serum metformin level 2 h after ingestion was 267 mg/L (therapeutic range, 0.465-2.5), and serum insulin was 2 mU/L (normal range, 6-35). Extensive laboratory investigation using high-resolution mass-spectrometry ruled out other possible hypoglycemic agents. She recovered after hemodialysis.
  
  
  CONCLUSIONS
  Metformin overdose can cause severe hypoglycemia in the absence of other antidiabetic drugs. Potential mechanisms of metformin-induced hypoglycemia include decreased hepatic glucose production, decreased glucose absorption, and poor oral intake.
authors.affiliation: San Francisco Division, California Poison Control System, University of California, San Francisco, CA, USA.
authors.forename: S A
authors.initials: SA
authors.lastname: Al-Abri
authors.forename: S
authors.initials: S
authors.lastname: Hayashi
authors.forename: K L
authors.initials: KL
authors.lastname: Thoren
authors.forename: K R
authors.initials: KR
authors.lastname: Olson
mesh_terms: D000140:Acidosis, Lactic / Q000139:chemically induced / Q000503:physiopathology; D000293:Adolescent; D062787:Drug Overdose / Q000209:etiology* / Q000503:physiopathology / Q000628:therapy; D005260:Female; D006801:Humans; D007003:Hypoglycemia / Q000139:chemically induced* / Q000503:physiopathology / Q000628:therapy; D007004:Hypoglycemic Agents / Q000009:adverse effects*; D007022:Hypotension / Q000139:chemically induced / Q000503:physiopathology; D008687:Metformin / Q000009:adverse effects*; D006435:Renal Dialysis; D016896:Treatment Outcome
chemical_list: D007004:Hypoglycemic Agents; D008687:Metformin