acamprosate

General Information

Acamprosate (brand Campral; generics) is indicated to support maintenance of abstinence in alcohol use disorder (AUD) in people who are abstinent at treatment initiation (label).

It is not an acute alcohol withdrawal medication; withdrawal management is typically handled separately, then relapse-prevention options (such as acamprosate or naltrexone) are considered as follow-up care continues (guideline/clinical).

A practical differentiator is that acamprosate has minimal hepatic metabolism and is primarily renally eliminated. This can be helpful in people with liver disease but requires renal assessment and dose-adjustment constraints (label).

Evidence syntheses and guidelines describe modest but clinically meaningful benefits on abstinence outcomes when paired with structured support (review/guideline).

The compare view, acamprosate evidence feed, and acamprosate print page support shared decision-making when alcohol use disorder treatment is discussed alongside mood symptoms and relapse-risk planning.

Often selected when the treatment goal is abstinence and when liver disease or opioid co-use makes alternatives less suitable. Practical limitations include multiple daily dosing and GI tolerability.

Mechanism of Action

Refer to the Glossary entry on Neurotransmitters for background on receptor systems involved in serious mental illness.

The exact mechanism is not fully established. Label and review sources describe acamprosate as modulating glutamatergic and GABAergic systems, supporting neurochemical stabilization during abstinence (label/review).

It is best conceptualized as a relapse-prevention medication used after detoxification rather than as a medication that treats acute withdrawal symptoms (guideline/clinical).

• Glutamatergic/GABAergic modulation (mechanism not fully established).

Metabolism and Pharmacokinetics

• Not significantly metabolized; eliminated primarily as unchanged drug in urine (label).
• Renal impairment increases exposure; labeling recommends dose reduction in moderate renal impairment and avoidance in severe renal impairment (label).
• Steady-state is reached over several days with regular dosing; the elimination half-life is on the order of a day (label).

Dosing and Administration

• Label dosing is divided across the day (often three times daily) and is started after abstinence is achieved (label/guideline).
• Dose reduction is recommended in moderate renal impairment and the medication is not recommended in severe renal impairment (label).
• When adherence to multiple daily dosing is a major barrier, clinicians often discuss alternative relapse-prevention strategies rather than persisting with a regimen unlikely to be taken consistently (clinical).

Monitoring & Labs

• Confirm abstinence at initiation and align expectations that acamprosate is a relapse-prevention support, not an acute withdrawal medication (label/guideline).
• Renal function: assess baseline kidney function and re-check if renal disease is present or if clinical status changes; dose-adjust per label (label/clinical).
• Monitor GI tolerability (diarrhea) and adherence, especially in the first weeks when drop-off is common (label/clinical).
• Monitor mood and suicidality as part of standard care for alcohol use disorder with co-occurring depression/anxiety (label/clinical).

Medication choice is commonly revisited after early stabilization to ensure the regimen matches the person’s goals (abstinence vs reduction), medical comorbidities, and ability to adhere to the dosing schedule.

Adverse Effects

Interactions

• Pharmacokinetic interactions are limited because acamprosate is not significantly metabolized and is largely excreted unchanged (label).
• Co-treatment is common in alcohol use disorder care (antidepressants, sleep agents, analgesics), so regimen review usually focuses on overall sedation risk, hepatic/renal constraints, and adherence (clinical).

Other Useful Information

• Evidence syntheses show acamprosate improves continuous abstinence and related outcomes versus placebo, with best results when started after detoxification and paired with counseling (review/guideline).
• Guidelines often position acamprosate and naltrexone as first-line pharmacotherapies, with selection based on liver/renal factors and the person’s abstinence vs reduction goals (guideline).
• Because it is not an opioid antagonist, acamprosate can be an option when opioid analgesics are required and naltrexone would be incompatible (clinical).

References

1. Acamprosate Calcium Delayed Release Tablets Prescribing Information — DailyMed (2025)
2. Pharmacotherapy FOR Adults With Alcohol USE Disorders IN Outpatient Settings: A Systematic Review AND Meta Analysis — JAMA (2014)
3. The American Psychiatric Association Practice Guideline for the Pharmacological Treatment of Patients With Alcohol Use Disorder — American Journal of Psychiatry (2018)
4. Anticraving therapy for alcohol use disorder: A clinical review — Neuropsychopharmacology Reports (2018)