Acamprosate calcium, a homotaurine analog, interacts with glutamate and γ-aminobutyric acid (GABA) neurotransmitter systems in the CNS.1, 7
Acamprosate calcium is used in the maintenance of abstinence from alcohol in patients with alcohol dependence who are abstinent at the time acamprosate therapy is initiated.1 Acamprosate should be used in conjunction with a comprehensive management program that includes psychosocial support.1 Acamprosate has not been shown to provide therapeutic benefit in individuals who have not undergone detoxification and have not achieved abstinence from alcohol ingestion prior to initiation of the drug.1 Whether acamprosate is effective in promoting abstinence from alcohol ingestion in individuals who abuse multiple substances has not been established to date.1
When used in conjunction with psychosocial support, acamprosate reportedly helps maintain abstinence from alcohol ingestion.1, 2, 3, 4 In several randomized, placebo-controlled clinical studies evaluating acamprosate as an adjunct to psychosocial therapy in alcohol-dependent patients who had undergone inpatient detoxification and were abstinent on the day of randomization, reported rates of abstinence throughout the duration of the studies (90-360 days) were higher in patients receiving acamprosate (18-45%) than in those receiving placebo (11-25%).1, 2, 3, 4, 7 However, in some randomized, placebo-controlled studies in alcohol-dependent patients who received little psychosocial support and who underwent detoxification but were not required to be abstinent at or near the time of study-drug initiation, rates of abstinence in patients receiving acamprosate were similar to rates in patients receiving placebo.5, 6, 7 Acamprosate was no more effective than placebo in a study in alcohol-dependent patients that included individuals who had a history of multiple-substance abuse and/or had not undergone detoxification; in addition, patients enrolled in this study were not required to be abstinent at study entry.1
Although comparative studies are limited, efficacy of acamprosate appears to be comparable to that of naltrexone.7, 8, 11 Acamprosate can be used in conjunction with naltrexone or disulfiram.7, 8, 9
Acamprosate calcium can be administered orally without regard to meals.1 However, for patients who regularly eat 3 meals a day, administration of the drug with meals may improve compliance.1
The recommended dosage of acamprosate calcium for maintenance of abstinence from alcohol ingestion in adults with normal renal function (creatinine clearance exceeding 50 mL/minute) is 666 mg 3 times daily.1 A lower dosage (1.3 g daily given in 3 unequally divided doses of 666, 333, and 333 mg each) also was evaluated in clinical studies and may be effective in some patients.1, 2, 3, 4, 11
Therapy with acamprosate should be initiated as soon as possible after alcohol withdrawal, when the patient has achieved abstinence from alcohol ingestion.1 Therapy with acamprosate can be continued even if the patient relapses.1
The recommended initial dosage of acamprosate calcium for maintenance of abstinence from alcohol ingestion in adults with moderate renal impairment (creatinine clearance of 30-50 mL/minute) is 333 mg 3 times daily.1 (See Cautions: Renal Impairment.) The drug is contraindicated in patients with severe renal impairment (creatinine clearance less than 30 mL/minute).1
No dosage adjustment is necessary in patients with mild to moderate hepatic impairment.1 (See Cautions: Hepatic Impairment.)
Dosage should be selected carefully in geriatric patients.1 (See Cautions: Geriatric Patients.)
Known hypersensitivity to acamprosate or any ingredient in the formulation.1
Severe renal impairment (creatinine clearance less than 30 mL/minute).1
Acamprosate does not eliminate or diminish withdrawal symptoms.1
In clinical studies of 1 year's duration, suicidality (i.e., suicidal ideation, suicide attempt, completed suicide) was reported more frequently in patients receiving acamprosate than in those receiving placebo (2.4 versus 0.8%).1 Completed suicide occurred in 0.13% of patients receiving acamprosate in clinical studies and in 0.1% of those receiving placebo.1 While many of these events occurred in the context of alcohol relapse, a consistent pattern between recovery from alcoholism and the emergence of suicidality was not identified.1 These studies excluded patients with severe psychiatric impairment,2, 3, 4, 5, 6 and review of safety data did not show a difference in the incidence of adverse events designated as depression between those receiving acamprosate and those receiving placebo.1 The existence of a relationship between alcohol dependence, depression, and suicidality is well known.1
Closely monitor patients for symptoms of depression and suicidal thinking.1
Category C. (See Users Guide.)
Acamprosate is distributed into milk in rats; caution if used in nursing women.1
Safety and efficacy not established in children younger than 18 years of age.1, 13 Acamprosate has been evaluated in a limited number of adolescents 16-19 years of age.10
Experience in those 65 years of age or older insufficient to determine whether they respond differently than younger adults.1
Pharmacokinetics not evaluated in geriatric individuals.1 Because geriatric patients frequently have decreased renal function, plasma concentrations of acamprosate are expected to be higher in geriatric individuals than in younger adults.1 Select drug dosage carefully.1 Consider monitoring renal function.1
Pharmacokinetics not altered in patients with mild or moderate hepatic impairment (Child-Pugh class A or B).1 Safety and pharmacokinetics not evaluated in patients with severe hepatic impairment.13
Acamprosate is eliminated in urine as unchanged drug; clearance depends on renal function.1 Dosage adjustment recommended in patients with creatinine clearance of 30-50 mL/minute.1 (See Dosage and Administration: Special Populations.) Contraindicated in patients with creatinine clearance less than 30 mL/minute.1
Adverse effects reported in 5% or more of patients receiving acamprosate and more frequently than placebo include diarrhea1, 2, 3, 4, 5, 6 and asthenia.1
Safety profile in patients receiving acamprosate in conjunction with anxiolytics, hypnotics and sedatives (including benzodiazepines), or nonopiate analgesics in clinical studies was similar to that in patients receiving these drugs with placebo.1
Pharmacokinetic interaction unlikely.1
Changes in weight (i.e., loss or gain) reported more frequently in patients receiving acamprosate concomitantly with an antidepressant than in patients receiving either agent alone.1
No change in the pharmacokinetics of desipramine or imipramine.1
Pharmacokinetic interaction unlikely.1
Pharmacokinetic interaction unlikely.1
Pharmacokinetic interaction (increased plasma concentrations of acamprosate; no change in plasma concentrations of naltrexone or its major metabolite, 6-β-naltrexol).1, 12 No dosage adjustment recommended.1
Acamprosate calcium is a synthetic homotaurine derivative and is structurally related to γ-aminobutyric acid (GABA).1, 7
While the precise mechanism of action of acamprosate in the maintenance of abstinence from alcohol ingestion remains to be determined, the drug decreases glutamatergic transmission and modulates neuronal hyperexcitability during withdrawal from alcohol.7 Acamprosate reduces voluntary intake of alcohol in alcohol-dependent animals. 1, 7 Acamprosate did not exhibit anticonvulsant, antidepressant, or anxiolytic activity in animal studies.1 Administration of acamprosate was not associated with the development of tolerance or dependence in animal studies.1 Acamprosate is not known to cause alcohol aversion.1 Ingestion of alcohol by individuals receiving acamprosate therapy does not result in a disulfiram-like reaction.1
Acamprosate is eliminated principally in urine as unchanged drug.1 The drug is not metabolized in the liver.1 Acamprosate does not induce cytochrome P-450 (CYP) isoenzymes 1A2 or 3A4, nor does it inhibit CYP isoenzymes 1A2, 2C9, 2C19, 2D6, 2E1, or 3A4.1
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.1
Importance of continuing acamprosate as directed by their clinician, even in the event of a relapse.1 Importance of discussing any renewed use of alcohol with their clinician.1
Advise patients that acamprosate helps maintain abstinence only when used as part of a treatment program that includes counseling and other supportive measures.1
Risk of suicidality; importance of patients, families, and caregivers notifying clinicians of emergence of suicidality or symptoms of depression.1
Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.1
Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs, as well as any concomitant illnesses.1
Importance of informing patients of other important precautionary information.1 (See Cautions.)
Additional Information
The American Society of Health-System Pharmacists, Inc. represents that the information provided in the accompanying monograph was formulated with a reasonable standard of care, and in conformity with professional standards in the field. Readers are advised that decisions regarding use of drugs are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and that the information contained in the monograph is provided for informational purposes only. The manufacturer's labeling should be consulted for more detailed information. The American Society of Health-System Pharmacists, Inc. does not endorse or recommend the use of any drug. The information contained in the monograph is not a substitute for medical care.
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.
AHFS® Drug Information. © Copyright, 1959-2025, Selected Revisions May 10, 2024. American Society of Health-System Pharmacists, Inc., 4500 East-West Highway, Suite 900, Bethesda, MD 20814.
1. Forest Pharmaceuticals, Inc. Campral® (acamprosate calcium) delayed-release tablets prescribing information. St. Louis, MO; 2004 Jul.
2. Sass H, Soyka M, Mann K et al. Relapse prevention by acamprosate: results from a placebo-controlled study on alcohol dependence. Arch Gen Psychiatry . 1996: 53:673-80.
3. Paille FM, Guelfi JD, Perkins AC et al. Double-blind randomized multicentre trial of acamprosate in maintaining abstinence from alcohol. Alcohol Alcohol . 1995: 30:239-47.
4. Pelc I, Verbanck P. LeBon O et al. Efficacy and safety of acamprosate in the treatment of detoxified alcohol-dependent patients: a 90-day placebo-controlled dose-finding study. Br J Psychiatry . 1997; 171:73-7. [PubMed 9328500]
5. Chick J, Howlett H, Morgan MY et al. United Kingdom multicentre acamprosate study (UKMAS): a 6-month prospective study of acamprosate versus placebo in preventing relapse after withdrawal from alcohol. Alcohol Alcohol . 2000; 35:176-87. [PubMed 10787394]
6. Namkoong K, Lee B-O, Lee P-G et al. Acamprosate in Korean alcohol-dependent patients: a multicentre, randomized, double-blind, placebo-controlled study. Alcohol Alcohol . 2003: 38:135-41.
7. Anon. Acamprosate (Campral) for alcoholism. Med Lett Drugs Ther . 2005: 47:1-3.
8. Kiefer F, Jahn H, Tarnaske T et al. Comparing and combining naltrexone and acamprosate in relapse prevention of alcoholism: a double-blind, placebo-controlled study. Arch Gen Psychiatry . 2003; 60:92-9. [PubMed 12511176]
9. Besson J, Aeby F, Kasas A et al. Combined efficacy of acamprosate and disulfiram in the treatment of alcoholism: a controlled study. Alcohol Clin Exp Res . 1998; 22:573-9. [PubMed 9622434]
10. Niederhofer H, Staffen W. Acamprosate and its efficacy in treating alcohol dependent adolescents. Eur Child Adolesc Psychiatry . 2003; 12:114-8. [PubMed 12768458]
11. Bouza C, Margro A, Muñoz A et al. Efficacy and safety of naltrexone and acamprosate in the treatment of alcohol dependence: a systematic review. Addiction . 2004; 99:811-28. [PubMed 15200577]
12. Mason BJ, Goodman AM, Dixon RM et al. A pharmacokinetic and pharmacodynamic drug interaction study of acamprosate and naltrexone. Neuropsychopharmacology . 2002; 27:596-606. [PubMed 12377396]
13. Forest Research Institute, Jersey City, NJ: Personal communication.