Pharmacology · Medicines for alcohol use disorder
Acamprosate !
A medicine that helps people who have stopped drinking stay abstinent. It is not metabolised and leaves through the kidneys, so it suits liver disease.
Updated 2026-11-01
Mechanism of action
Long-term drinking leaves the brain with too much glutamate excitation and too little GABA inhibition once alcohol stops, which feeds craving. Acamprosate (N-acetylhomotaurine) is thought to rebalance these two systems; its exact mechanism is not known.
- After stopping alcohol, glutamate excitation runs high
- Acamprosate helps rebalance glutamate and GABA
- Craving falls and abstinence is easier to keep
Pharmacokinetics
- Absorption
- Low bioavailability by mouth, about 11%
- Metabolism
- Not metabolised
- Elimination
- Unchanged through the kidneys
- Half-life
- About 20 to 33 hours (terminal)
Indications
- Keeping abstinence in alcohol dependence, in people already abstinent, with psychosocial support Alcohol use disorder →
Adverse effects
Common
- Diarrhoea (the most frequent)
- Insomnia and weakness
- Itching, nausea and flatulence
Contraindications
- Severe kidney impairment
- Hypersensitivity to acamprosate
Key interactions
- Naltrexone
- Modestly higher acamprosate levels; not clinically important
- Alcohol, disulfiram, diazepam
- Do not change acamprosate kinetics
What is monitored
- Kidney function (creatinine clearance) before and during treatment
- Mood and suicidal thoughts
- Drinking and relapse
Administration and safety
- Given by mouth as delayed-release tablets, with or without food
- Started after alcohol withdrawal is over, as part of a support programme
- Continued even if a relapse occurs
Nursing care
- Check kidney function before the first dose
- Ask about mood and thoughts of self-harm at each visit
- Teach that it does not stop withdrawal symptoms or cause a reaction with alcohol
- Encourage counselling or support groups
Pregnancy and breastfeeding
Used in pregnancy only if the benefit justifies the risk; animal studies showed malformations.
Test yourself
Think of the answer, then tap the question to see it.
Why is acamprosate a good option in alcoholic liver disease?
It is not metabolised by the liver and is excreted unchanged in the urine.
When is acamprosate started?
Once the person is abstinent; it does not relieve withdrawal.
What is the most frequent adverse effect of acamprosate?
Diarrhoea.
Related drugs
Related conditions
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Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: DailyMed - ACAMPROSATE CALCIUM tablet, delayed release (DailyMed (U.S. National Library of Medicine), 2026); Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed., ch. 27 (McGraw Hill, 2023); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026).
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Representative model, for educational purposes only.