USMLE Prep - Medical Reference Library

Methanol Ethylene Glycol Poisoning — Fomepizole and Dialysis

System: Toxicology • Reviewed: Aug 31, 2025 • Step 1Step 2Step 3

Synopsis:

Suspect in high anion gap metabolic acidosis with osm gap; give fomepizole promptly, correct acidosis, and arrange hemodialysis for standard indications.

Key Points

  • Stabilize ABCs; begin targeted evaluation without delaying life-saving therapy.
  • Use system-specific risk tools to guide testing and disposition.
  • Order high-yield tests first; escalate imaging when indicated.
  • Start evidence-based initial therapy and reassess frequently.

Algorithm

  1. Primary survey and vitals; IV access and monitors.
  2. Focused history/physical; identify red flags and likely etiologies.
  3. Order system-appropriate labs and imaging (see Investigations).
  4. Initiate guideline-based empiric therapy (see Pharmacology).
  5. Reassess response; arrange consultation and definitive management.

Clinical Synopsis & Reasoning

For Toxic Alcohols Fomepizole Dialysis, frame the differential by acuity and pathophysiology, then align diagnostics to the leading hypotheses. Prioritize stabilization while obtaining high‑yield studies such as CBC (Baseline hematology), BMP (Electrolytes/renal). Incorporate bedside imaging and targeted labs to define severity and identify complications; synthesize results with clinical trajectory to refine the working diagnosis and disposition needs.


Treatment Strategy & Disposition

Initiate disease‑directed therapy alongside supportive care, titrating to objective response. Pharmacologic options commonly include Analgesia/Antipyretics. Use validated frameworks (e.g., Adjunctive Cofactors) to guide escalation and site of care. Address precipitating factors, de‑escalate empiric therapies with data, and arrange follow‑up for monitoring and risk‑factor modification; admit patients with instability, high risk of deterioration, or needs for close monitoring.


Epidemiology / Risk Factors

  • Risk factors vary by condition and patient profile

Investigations

TestRole / RationaleTypical FindingsNotes
CBCBaseline hematologyAbnormal counts
BMPElectrolytes/renalDerangements

Adjunctive Cofactors

Toxic alcoholCofactor
MethanolFolate folinic acid
Ethylene glycolThiamine and pyridoxine

Pharmacology

MedicationMechanismOnsetRole in TherapyLimitations
FomepizoleADH inhibitionMinutesAntidote; prevents toxic metabolitesHeadache
Sodium bicarbonateAlkalinize serumMinutesSevere acidosisHypokalemia
HemodialysisExtracorporeal removalHoursSevere poisoning/renal failureAccess issues

Prognosis / Complications

  • Prognosis depends on severity, comorbidities, and timeliness of care

Patient Education / Counseling

  • Explain red flags and when to seek emergent care.
  • Reinforce medication adherence and follow-up plan.

Notes

Consider differential for osm gap such as ketoacidosis or mannitol. Avoid ethanol therapy unless fomepizole unavailable and expertise exists.


References

  1. EXTRIP Workgroup — Methanol Ethylene Glycol — Link
  2. CDC NIOSH Toxic Alcohols — Link