What is Acamprosate used for?

Acamprosate for Alcohol Dependence Treatment

Acamprosate is primarily used to maintain abstinence in alcohol-dependent patients after detoxification, with moderate evidence showing it reduces relapse rates and increases abstinence duration compared to placebo. 1, 2

Mechanism and Efficacy

• Acamprosate works by modulating glutamate and GABA neurotransmitter systems, helping to restore neurochemical balance disrupted by chronic alcohol use 2, 3
• Increases odds of abstinence by 86% compared to placebo (OR 1.86,95% CI 1.49-2.33) 2
• Most effective when initiated 3-7 days after last alcohol consumption 2
• Particularly effective for maintaining abstinence rather than inducing it 1
• Has demonstrated efficacy in more than 25 placebo-controlled trials 4

Administration and Dosing

• Recommended dosage: 1.3 g/day for patients weighing <60 kg and 2 g/day for patients weighing ≥60 kg 5
• Typically administered as 333 mg enteric-coated tablets taken three times daily 5
• Alternative dosing: 500 mg twice daily is bioequivalent to 333 mg three times daily 5
• Treatment should continue for at least 3-6 months, with longer treatment potentially more effective 2

Advantages Over Other Medications

• No hepatotoxicity concerns, making it suitable for patients with liver disease (unlike naltrexone or disulfiram) 2, 4
• Can be safely administered to patients who continue drinking alcohol 4
• Moderate side effect profile with primarily mild gastrointestinal effects (especially diarrhea) 6
• Not protein-bound or metabolized in the liver 5

Clinical Considerations

• Should be used as part of a comprehensive treatment approach that includes psychosocial support or counseling 2
• Contraindicated in patients with renal insufficiency as it is primarily eliminated unchanged in urine 5
• Food decreases absorption, so consistent administration relative to meals is recommended 5
• No evidence of abuse potential or withdrawal symptoms upon discontinuation 6
• No significant drug interactions with diazepam, disulfiram, or alcohol 5

Treatment Selection Algorithm

1. For patients requiring maintenance of alcohol abstinence after detoxification:

   • First-line: Acamprosate (if no renal impairment)
   • Alternative: Naltrexone (if liver function normal) or baclofen (if liver disease present)

2. For patients with comorbid conditions:

   • Liver disease: Acamprosate preferred over naltrexone or disulfiram
   • Renal disease: Avoid acamprosate, consider naltrexone
   • Continued drinking: Acamprosate can still be used safely

3. For optimal outcomes:

   • Combine with counseling or support groups
   • Monitor adherence regularly
   • Continue treatment for at least 3-6 months

Limitations and Considerations

• Less effective for reducing heavy drinking days than for maintaining complete abstinence 4
• Efficacy not significantly improved by combining with naltrexone 4
• Absorption is limited after oral administration 5
• Steady-state is reached after 5-7 days of treatment 5

Acamprosate represents an important pharmacological option for maintaining abstinence in alcohol-dependent patients, with particular value for those with liver disease who cannot tolerate naltrexone or disulfiram.