Acute Alcohol Intoxication and Alcohol Use Disorder Pharmacotherapy
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Direct answer
Acute alcohol intoxication is managed supportively, with airway protection, glucose, thiamine and monitoring for hypoglycaemia and respiratory depression. Alcohol use disorder pharmacotherapy uses naltrexone to reduce heavy drinking, acamprosate to support abstinence and disulfiram to deter drinking through acetaldehyde build-up. Thiamine is always given before glucose to avoid precipitating Wernicke encephalopathy.
What you must remember
- Intoxication care: airway and breathing support, glucose checks and close monitoring, since aspiration and hypoglycaemia are the hidden dangers.
- Thiamine before glucose: given first in malnourished drinkers to prevent Wernicke encephalopathy.
- Naltrexone: an opioid antagonist that reduces heavy drinking and craving, contraindicated with opioid use and in acute hepatitis or liver failure.
- Acamprosate: modulates glutamate and GABA signalling to support abstinence, is not hepatically metabolised, and is avoided in significant renal impairment.
- Disulfiram: inhibits aldehyde dehydrogenase, so alcohol causes flushing, tachycardia and vomiting; it is given only to a sober patient who has consented.
- Withdrawal: benzodiazepines such as chlordiazepoxide are first-line, titrated against a structured score such as the CIWA-Ar.
- Delirium tremens: a medical emergency in withdrawal, marked by confusion, autonomic overactivity and hallucinations, needing urgent treatment.
Managing a patient brought in after binge drinking
A 40-year-old man is brought in drowsy after binge drinking, with slow, shallow breathing and low blood glucose. Each step addresses a danger that can kill before the alcohol itself is cleared. The blood alcohol level alone does not show how sick the patient is, so bedside priorities come first.
- Protect the airway: Position the patient to prevent aspiration, support breathing, and intubate if consciousness is lost and protective reflexes are absent.
- Check glucose: Measure blood glucose, because alcohol-induced hypoglycaemia is common and dangerous in malnourished patients.
- Give thiamine first: Thiamine is given before glucose to prevent precipitation of Wernicke encephalopathy, and glucose follows if needed.
- Correct electrolytes: Check potassium, magnesium, phosphate and acid-base status, since these are often deranged in chronic drinkers.
- Monitor for withdrawal: As intoxication wanes, track CIWA-Ar scores and watch for tremor, tachycardia, seizures and hallucinations.
- Plan relapse prevention: Once the acute episode settles, assess for alcohol use disorder and start a relapse-prevention drug.
Where the exam tries to catch you
Pharmacotherapy questions hinge on contraindications, which the options often hide in the stem.
- Trap: giving naltrexone to a patient on opioid analgesia or with liver failure. Correct: naltrexone blocks opioids and is contraindicated with opioid use or acute hepatitis and liver failure.
- Trap: giving disulfiram to an intoxicated patient to stop drinking. Correct: disulfiram causes a dangerous reaction with alcohol, so it is given only to a sober, consenting patient.
- Trap: choosing glucose before thiamine. Correct: thiamine comes first, since glucose can precipitate Wernicke encephalopathy in a thiamine-deficient drinker.
Frequently asked questions
Why is thiamine given before glucose in alcohol intoxication?
Thiamine is given before glucose in alcohol intoxication because glucose can precipitate Wernicke encephalopathy in thiamine-deficient patients. Alcohol use disorder commonly causes this deficiency, and thiamine given first protects against it.
How does disulfiram produce its effect in alcohol use disorder?
Disulfiram inhibits aldehyde dehydrogenase, so acetaldehyde accumulates when alcohol is consumed. The resulting reaction causes flushing, tachycardia, nausea and vomiting, which deters drinking in disulfiram-treated patients.
When is naltrexone contraindicated in alcohol use disorder?
Naltrexone is contraindicated in patients taking opioids and in those with acute hepatitis or liver failure. Because it is an opioid antagonist, it can also precipitate withdrawal in patients dependent on opioids.
Which relapse-prevention drug is preferred when kidney function is reduced?
Naltrexone is often preferred over acamprosate when kidney function is reduced, because acamprosate is renally cleared and avoided at low clearance. Naltrexone is metabolised in the liver, so it suits renal impairment provided there is no liver failure or opioid use.
What is the first-line drug for alcohol withdrawal?
Benzodiazepines such as chlordiazepoxide are first-line drugs for alcohol withdrawal, titrated against a structured score such as the CIWA-Ar. They control tremor, autonomic overactivity and seizures, and they are the key treatment for delirium tremens.