Ethanol Dosing for Ethylene Glycol Intoxication
Loading and Maintenance Dose
For ethanol as an antidote in ethylene glycol poisoning, administer a loading dose of 600-800 mg/kg (approximately 7.5-10 mL/kg of 10% ethanol solution IV), followed by a maintenance infusion of 100-150 mg/kg/hour, titrated to maintain a serum ethanol concentration of 100-150 mg/dL (22-33 mmol/L). 1
Practical Administration Details
- Intravenous route preferred: Use 10% ethanol in D5W as the standard preparation for IV administration 1
- Oral alternative when IV unavailable: Oral ethanol (whisky or other spirits) can be administered via nasogastric tube at equivalent doses, though monitoring is more challenging 2
- Target serum level: Maintain ethanol concentration between 100-150 mg/dL throughout treatment 1
Critical Dosing Adjustments
During hemodialysis, ethanol dosing must be substantially increased because ethanol is dialyzable:
- Increase maintenance rate to approximately 250-350 mg/kg/hour during intermittent hemodialysis 3, 1
- Some protocols recommend dosing every 4 hours during dialysis rather than continuous infusion 1
- Monitor ethanol levels frequently (every 2-4 hours) during extracorporeal treatment 3
When Ethanol Should Be Used
Ethanol is indicated when fomepizole is unavailable, as fomepizole is the preferred antidote due to more predictable pharmacokinetics and fewer adverse effects. 1
Indications for Extracorporeal Treatment When Using Ethanol
The threshold for adding hemodialysis is lower when ethanol (rather than fomepizole) is the antidote:
- Recommend hemodialysis if ethylene glycol concentration >50 mmol/L (>310 mg/dL) OR osmol gap >50 3
- Suggest hemodialysis if ethylene glycol concentration 20-50 mmol/L (124-310 mg/dL) OR osmol gap 20-50 3
- Recommend hemodialysis if anion gap >27 mmol/L or glycolate concentration >12 mmol/L 3, 1
- Recommend hemodialysis for severe clinical features: coma, seizures, or acute kidney injury (KDIGO stage 2 or 3) 3
Rationale for Lower Threshold with Ethanol
The EXTRIP workgroup uses stronger recommendations (recommend vs. suggest) for hemodialysis when ethanol is used because:
- ADH blockade with ethanol is unpredictable and treatment failures occur even with minimal acidosis on admission 3
- Prolonged ethanol therapy carries significant risks: CNS depression, dysphoria, and requires high-dependency unit admission 3
- Subtherapeutic ethanol levels are common due to variable metabolism and inadequate monitoring, leading to continued toxic metabolite formation 4
Common Pitfalls to Avoid
- Inadequate monitoring: Ethanol levels must be checked every 2-4 hours initially, then every 4-6 hours once stable, as metabolism varies widely between patients 1
- Forgetting dialysis adjustment: Failure to increase ethanol dosing during hemodialysis leads to subtherapeutic levels and continued toxicity 3, 1
- Alcohol withdrawal: Patients with alcohol use disorder may develop withdrawal symptoms during treatment; monitor and treat accordingly 1
- Relying on osmol gap alone: A normal osmol gap (0-12 mOsm/kg) does not rule out late-presenting ethylene glycol poisoning, as the parent compound may already be metabolized; check anion gap and glycolate levels 5
Duration of Treatment
Continue ethanol therapy until:
- Ethylene glycol concentration <4 mmol/L (25 mg/dL) 3
- Anion gap normalizes to <18 mmol/L 3, 1
- Metabolic acidosis resolves 3
With ethylene glycol concentration >50 mmol/L and endogenous half-life of 14 hours during ethanol therapy, expect treatment duration >48 hours, during which risks of ethanol side effects and therapeutic failure become substantial—this is why hemodialysis is strongly recommended at this threshold 3.