Psychiatry/Alcohol dependence drugs

Alcohol dependence & withdrawal

also: chlordiazepoxide · pabrinex · thiamine · acamprosate · disulfiram · Wernicke

Overview

Managing alcohol withdrawal and preventing relapse. The thiamine-before-glucose rule (Wernicke) and the benzodiazepine detox regimen are core.

Mechanism

Withdrawal is GABA underactivity + glutamate overactivity → a reducing benzodiazepine (chlordiazepoxide) substitutes for alcohol's GABA effect, preventing seizures/delirium tremens. Thiamine replaces the deficiency that causes Wernicke. Relapse-prevention agents reduce craving (acamprosate), reward (naltrexone) or create aversion (disulfiram).

Indications

Acute alcohol withdrawal
Wernicke encephalopathy prophylaxis/treatment
Relapse prevention

The agents

Chlordiazepoxide (reducing regimen)withdrawal

tapered over days

Long-acting benzo prevents seizures/DTs; lorazepam if liver failure.

Thiamine (Pabrinex)Wernicke prophylaxis

IV/IM then oral

Give BEFORE/with glucose — glucose first can precipitate Wernicke.

Acamprosaterelapse — craving

Reduces craving (modulates glutamate).

Naltrexonerelapse — reward

Opioid antagonist; do not use in opioid users.

Disulfiramrelapse — aversion

Blocks acetaldehyde dehydrogenase → flushing/vomiting with any alcohol.

Adverse effects

Wernicke–Korsakoff if thiamine omittedserious

Confusion, ophthalmoplegia, ataxia → irreversible Korsakoff.

Disulfiram–alcohol reactionserious

Even mouthwash/perfume; counsel.

Over-sedation from benzodiazepine (esp. liver impairment)common

Cautions & contraindications

IV glucose before thiamine in alcohol dependenceall

Precipitates Wernicke encephalopathy.

Disulfiram with any alcohol / ischaemic heart diseaseall

Interactions

Disulfiram + alcohol/metronidazole
Benzo + other CNS depressants

Monitoring & kinetics

Withdrawal score (CIWA); LFTs

Benzo tapered over ~5–7 days; relapse agents oral.

Source: NICE CG115 — Alcohol-use disorders · BNF — Alcohol dependence