Methanol / Ethylene Glycol Poisoning — Management Pathway

Step-by-step decision

Choose step by step as prompted; reaching an endpoint gives the management recommendation. You can go back a step or restart anytime.

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Full pathway

1. [Decision] Start the antidote?
   High-anion-gap acidosis + suspected toxic-alcohol ingestion — start the antidote? (Methanol (windshield fluid/industrial solvent/counterfeit liquor) and ethylene glycol (antifreeze, sweet) are metabolized by alcohol dehydrogenase (ADH) into toxic acids — methanol → formic acid (visual injury/blindness), ethylene glycol → oxalate (AKI/hypocalcemia). Diagnosis: high-anion-gap acidosis + raised osmolar gap (a normal osmolar gap does not exclude it and falls as metabolism proceeds; serial anion gap q2–4 h is sensitive); calcium oxalate crystalluria (ethylene glycol); confirm with drug levels.)
   • Confirmed/highly suspected (raised osmolar gap or unexplained high-AG acidosis) → Antidote → fomepizole ± dialysis
   • Possible, not yet supported → Possible · serial monitoring
2. [End] Possible · serial monitoring
   Serially monitor the anion gap (q2–4 h, very sensitive for toxic alcohols), osmolar gap, blood gas, renal function, vision; check blood methanol/ethylene glycol levels; co-ingested ethanol can delay the acidosis. Start the antidote the moment a high-AG acidosis or raised osmolar gap appears.
3. [End] Antidote → fomepizole ± dialysis
   1) ADH inhibitor fomepizole (first-line) 15 mg/kg loading → 10 mg/kg q12h (q4h on dialysis), until the level is <20–30 mg/dL, acidosis is corrected and asymptomatic; ethanol (target ~100–150 mg/dL) if fomepizole is unavailable. 2) Sodium bicarbonate for severe acidosis (pH <7.3). 3) Cofactors: folate/folinic acid for methanol, thiamine + pyridoxine for ethylene glycol. 4) Hemodialysis — severe acidosis (pH <7.25–7.3), end-organ damage (methanol vision / ethylene glycol AKI), refractory electrolyte disturbance, very high levels, clinical deterioration (methanol more often needs dialysis). Poison center/toxicology consult.

Source guidelines & references

• EXTRIP indications for extracorporeal removal in toxic alcohols; UpToDate methanol and ethylene glycol poisoning

This pathway is our own synthesis of the decision logic in the guidelines above (not the guideline verbatim); thresholds and workflows change as guidelines update — in practice follow the latest guideline, your institution's protocol and the individual patient.

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