Toxic Alcohol Ingestion - Ethylene Glycol

Author: Michelle Lin, MD
Updated: 6/8/2012

Toxic Alcohol Ingestion: Ethylene Glycol

General concepts for all 3 toxic alcohols

  • Parent compounds (not metabolites) cause high osmolal gap
  • When NAD depleted, pyruvate converts to lactate, which then causes lactic acidosis
  • See metabolism diagram below

Ethylene Glycol (EG): Factoids

Found in antifreeze, coolants, deicing solutions, ink in stamp pads and ballpoint pens

Pharmacology:

  • Peak serum concentration 1-4 hours, elimination half-life 3 hours
  • Minimum lethal dose 1-1.5 mL/kg
  • Metabolites (eg. oxalate acid) cause toxicity, but do NOT cause osmolal gap

Labs:

  • High anion gap metabolic acidosis and high osmolal gap (early in patient course)

Classic Presentation

  1. Altered mental status
  2. Hypocalcemia
  3. Oxalate crystals in urine

Common Signs and Symptoms

  • Neurologic – Nausea and vomiting, inebriation with euphoria, nystagmus, ataxia, myoclonic jerks… then CNS depression, hypotonia, seizures, coma
  • Cardiopulmonary – Hyperventilation from respiratory compensation of acidosis, hypoxia from heart failure, multiorgan failure, ARDS
  • Renal – Flank pain, acute tubular necrosis, renal failure

Management

  • Goal: Prevent further formation of (fomipezole) & eliminate toxic metabolites (dialysis)
  • Antidote: Fomipezole inhibits alcohol dehydrogenase (alternative antidote= ethanol)
  • Loading dose: 15 mg/kg IV
  • Maintenance dose: 10 mg/kg IV every 12 hours x 2 days

American Academy of Clinical Toxicology guidelines

Indications for treatment of EG poisoning with FOMIPEZOLE: (any of following)

  • Documented plasma ethylene glycol >20 mg/dL
  • Documented recent hx of ingesting toxic EG amounts and osmolal gap >10 mOsm/L

  • Strong suspicion of EG poisoning and at least 2 criteria:

    1. Arterial pH <7.3
    2. Serum bicarbonate <20 mEq/L
    3. Osmolal gap >10 mOsm/L
    4. Urine oxalate crystal present

Indications for treatment of EG toxicity with HEMODIALYSIS: (any of following)

  1. Deteriorating clinical status despite supportive tx PLUS metabolic acidosis (arterial pH < 7.25-7.3)
  2. Acute kidney injury with serum Cr > 3 mg/dL or increase in serum Cr by 1 mg/dL
  3. Acid-base/electrolyte abnormalities unresponsive to standard tx
  4. Old recommendation: EG level > 50 mg/dL

Note: Fomipezole without hemodialysis is an option if normal renal function AND no metabolic acidosis

Metabolism of Alcohols

Metabolism of alcohols drawing

References

  • Marraffa JM, Cohen V, Howland MA. Antidotes for toxicological emergencies: a practical review. Am J Health Syst Pharm. 2012 Feb 1;69(3):199-212. doi: 10.2146/ajhp110014. [PubMed]
  • Kraut JF, Kurtz I. Toxic alcohol ingestions: clinical features, diagnosis, and management. Clin J Am Soc Nephrol. 2008 Jan;3(1):208-25. Epub 2007 Nov 28. [PubMed]
  • Jammalamadaka D, Raissi S. Ethylene glycol, methanol and isopropyl alcohol intoxication. Am J Med Sci. 2010 Mar;339(3):276-81. doi: 10.1097/MAJ.0b013e3181c94601. [PubMed]