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Acamprosate (Monograph)

Brand name: Campral
Drug class: Central Nervous System Agents, Miscellaneous
VA class: AD100
Chemical name: Calcium 3-(acetylamino)propane-1-sulfonate
Molecular formula: C10H20CaN2O8S2
CAS number: 77337-73-6

Medically reviewed by on Apr 21, 2023. Written by ASHP.


Synthetic homotaurine derivative that interacts with glutamate and GABA neurotransmitter systems in the CNS.

Uses for Acamprosate

Alcohol Dependence

Maintenance of abstinence from alcohol in patients with alcohol dependence who are abstinent at the time acamprosate therapy is initiated.

Should be used in conjunction with a comprehensive management program that includes psychosocial support.

Therapeutic benefit not established in patients who have not undergone detoxification and have not achieved abstinence from alcohol ingestion.

Efficacy not established for the promotion of abstinence from alcohol ingestion in patients who abuse multiple substances.

Can be used in conjunction with naltrexone or disulfiram.

Acamprosate Dosage and Administration


Initiate therapy as soon as possible after the patient has achieved abstinence from alcohol ingestion.

Therapy can be continued even if the patient relapses.


Oral Administration

Administer orally 3 times daily without regard to meals. For individuals who regularly eat 3 meals a day, administer with meals (to improve compliance).


Available as acamprosate calcium; dosage expressed in terms of the salt.


Alcohol Dependence
Maintenance of Abstinence of Alcohol Ingestion

666 mg 3 times daily.

A lower dosage (1.3 grams daily given in 3 unequally divided doses of 666, 333, and 333 mg) also evaluated in clinical studies and may be effective in some patients.

Special Populations

Hepatic Impairment

Dosage adjustment not required in patients with mild to moderate hepatic impairment. (See Hepatic Impairment under Cautions.)

Renal Impairment

In patients with moderate renal impairment (Clcr 30–50 mL/minute), 333 mg 3 times daily. (See Renal Impairment under Cautions.)

Do not use in patients with severe renal impairment (Clcr<30 mL/minute). (See Contraindications under Cautions.)

Geriatric Patients

Select dosage carefully. (See Geriatric Use under Cautions.)

Cautions for Acamprosate


  • Known hypersensitivity to acamprosate or any ingredient in the formulation.

  • Severe renal impairment (Clcr <30mL/minute).


General Precautions

Withdrawal Symptoms

Does not eliminate or diminish withdrawal symptoms.


Increased risk of suicide in substance abusers with or without depression.

Suicidality (i.e., suicidal ideation, suicide attempt) and completed suicide reported.

Monitor for symptoms of depression and suicidal thinking.

Specific Populations


Category C.


Distributed into milk in rats; not known whether distributed into human milk. Use caution.

Pediatric Use

Safety and efficacy not established in children <18 years of age.

Evaluated in a limited number of adolescents 16–19 years of age.

Geriatric Use

Insufficient experience in patients ≥65 years of age to determine whether geriatric patients respond differently than younger adults; select dosage with caution.

Increased plasma concentrations in patients with renal impairment; assess renal function periodically since geriatric patients are more likely to have decreased renal function.

Hepatic Impairment

Pharmacokinetics not altered in patients with mild to moderate hepatic impairment (Child-Pugh class A or B). Safety and pharmacokinetics not evaluated in patients with severe hepatic impairment.

Renal Impairment

Clearance decreased depending on degree of renal impairment.

Dosage adjustment necessary in patients with Clcr 30–50 mL/minute. (See Renal Impairment under Dosage and Administration.)

Contraindicated in severe renal impairment (Clcr <30 mL/minute).

Common Adverse Effects

Diarrhea and asthenia.

Interactions for Acamprosate

Does not induce CYP isoenzymes 1A2 or 3A4; does not inhibit CYP isoenzymes 1A2, 2C9, 2C19, 2D6, 2E1, or 3A4.

Concomitant use with anxiolytics, hypnotics and sedatives (including benzodiazepines), or nonopiate analgesics not associated with changes in safety profile.

Specific Drugs





Pharmacokinetic interaction unlikely


Antidepressants: Changes in weight (i.e., loss or gain) reported

Desipramine: No change in pharmacokinetics of the antidepressant

Imipramine: No change in pharmacokinetics of the antidepressant


Pharmacokinetic interaction unlikely


Pharmacokinetic interaction unlikely


Increased concentrations of acamprosate; no change in concentrations of naltrexone or its major metabolite, 6-β-naltrexol

No dosage adjustment recommended

Acamprosate Pharmacokinetics



Absolute bioavailability is 11%.


Food reduces peak plasma concentrations by 42% and AUC by 23%; effect not considered clinically important.


Plasma Protein Binding




Does not undergo metabolism.

Elimination Route

Excreted principally in urine as unchanged drug.


20–33 hours.

Special Populations

In patients with moderate or severe renal impairment, peak plasma concentrations are 2-fold or 4-fold higher, respectively, than in healthy individuals. Half-life is 1.8-fold or 2.6-fold longer in patients with moderate or severe renal impairment, respectively, than in healthy individuals.





25°C (may be exposed to 15–30°C).


  • Decreases glutamatergic transmission and modulates neuronal hyperexcitability during withdrawal from alcohol.

  • Reduces voluntary intake of alcohol in alcohol-dependent animals. Acamprosate is not known to cause alcohol aversion.

  • Alcohol ingestion does not result in disulfiram-like reactions.

Advice to Patients

  • Risk of psychomotor impairment; importance of exercising caution while driving or operating hazardous machinery until the effects of the drug on the individual are known.

  • Risk of suicidality; importance of patients, families, and caregivers notifying clinicians of emergence of suicidality or symptoms of depression.

  • Importance of continuing therapy as directed by their clinician, even in the event of a relapse.

  • Importance of discussing any renewed use of alcohol with their clinician.

  • Advise patients that acamprosate helps maintain abstinence only when used as part of a treatment program that includes counseling and other supportive measures.

  • Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.

  • Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs, as well as any concomitant illnesses.

  • Importance of informing patients of other important precautionary information. (See Cautions)


Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

Acamprosate Calcium


Dosage Forms


Brand Names



Tablets, delayed-release (enteric-coated)

333 mg

Campral (with propylene glycol)


AHFS DI Essentials™. © Copyright 2023, Selected Revisions May 1, 2006. American Society of Health-System Pharmacists, Inc., 4500 East-West Highway, Suite 900, Bethesda, Maryland 20814.

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