Alcohol Poisoning: Symptoms, Causes & Treatment

Alcohol poisoning (acute alcohol intoxication) occurs when a person ingests enough ethanol in a short period to produce blood alcohol concentrations (BAC) that cause severe CNS and respiratory depression. The liver metabolizes alcohol at approximately 0.015 g/dL/hour regardless of the amount consumed; when ingestion rate exceeds this, BAC rises rapidly. Death can occur even after drinking stops, as alcohol in the gastrointestinal tract continues to be absorbed.

At BAC levels above 0.3 g/dL, progressive stupor, hypothermia, respiratory depression, loss of gag reflex, and seizures occur. Death typically results from: (1) asphyxiation from aspiration of vomitus while unconscious; (2) respiratory arrest from brainstem depression; (3) cardiac arrhythmias; or (4) severe hypoglycemia (alcohol inhibits hepatic gluconeogenesis). Thousands of alcohol poisoning deaths occur annually worldwide, disproportionately among young adults in binge-drinking contexts.

Critically, ethanol poisoning must be distinguished from poisoning by other alcohols: methanol (found in counterfeit alcohol, windshield washer fluid — causes optic neuropathy, blindness, and death; treated with fomepizole or ethanol antidote) and ethylene glycol (antifreeze — causes renal failure with oxalate crystals; also treated with fomepizole). Both present similarly initially but have vastly different prognoses and require immediate specific antidote therapy.

• Confusion, slurred speech, and ataxia (BAC 0.08–0.15 g/dL)
• Vomiting while consciousness is impaired — extreme risk of aspiration
• Stupor: cannot be easily roused (BAC >0.25 g/dL)
• Slow, shallow, or irregular respirations (<8 breaths/min) — sign of respiratory depression
• Cyanosis: blue lips or fingernails from hypoxemia
• Hypothermia: cold, pale, clammy skin
• Seizures (rare with pure ethanol; more common with methanol/ethylene glycol or withdrawal)
• Coma and respiratory arrest — immediately life-threatening (BAC >0.4 g/dL)

• Rapid ingestion of large amounts of ethanol (binge drinking — typically ≥4–5 drinks in 2 hours)
• Drinking on an empty stomach — food slows gastric emptying and delays peak BAC
• Young age and lower body mass — higher BAC per gram of alcohol consumed
• Concurrent CNS depressants: benzodiazepines, opioids, GHB — synergistic respiratory depression
• Non-ethanol alcohols: methanol (illicit distillates, windshield washer fluid) or ethylene glycol — more toxic; must be identified

Clinical diagnosis supplemented by: serum or breath ethanol level. Critical differential diagnosis — must exclude: hypoglycemia (fingerstick glucose immediately), head trauma (CT head if mechanism suggests), stroke, opioid or benzodiazepine overdose (give naloxone), CO poisoning. Anion gap metabolic acidosis with high osmol gap suggests methanol or ethylene glycol — order methanol and ethylene glycol levels urgently. Electrolytes, BMP, hepatic function, coagulation for severe intoxication management.

Immediate actions: never leave the person alone; if unconscious, place in recovery position (lateral decubitus) to prevent aspiration; call emergency services (112/911). Emergency department management: airway protection — endotracheal intubation if gag reflex absent or respiratory rate <8/min; supplemental oxygen; continuous monitoring (pulse oximetry, cardiac monitor). IV access: check glucose — give D50W (25 g IV) if hypoglycemic; give thiamine 100 mg IV before glucose in malnourished patients. Treat hypothermia with warming blankets. No specific antidote for ethanol — management is entirely supportive. For methanol/ethylene glycol: fomepizole (preferred antidote, inhibits alcohol dehydrogenase) or ethanol infusion + hemodialysis; do not delay.

• Aspiration of vomitus causing aspiration pneumonia or asphyxiation — the most common cause of alcohol poisoning death
• Respiratory arrest from medullary depression
• Severe hypoglycemia (especially in children and fasting adults) — seizures and permanent brain damage
• Severe hypothermia with cardiac arrhythmias
• Coma and death if untreated

• Education on binge drinking risks — particularly in adolescents and young adults
• Eat before and during drinking to slow ethanol absorption
• Never leave an intoxicated person alone, especially if vomiting
• Place unconscious intoxicated persons in the recovery position, never supine
• Avoid mixing alcohol with sedative drugs (benzos, opioids, sleep medications)
• Abstinence is the only guaranteed prevention; responsible drinking limits: ≤14 units/week UK or ≤2 drinks/day for men