Name: Acamprosate

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What other drugs will affect acamprosate?

Other drugs may interact with acamprosate, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.

Precautions While Using acamprosate

If you will be taking acamprosate for a long time, it is very important that your doctor check you at regular visits for any problems or unwanted effects that may be caused by acamprosate.

acamprosate may cause some people to be agitated, irritable or display other abnormal behaviors. It may also cause some people to have suicidal thoughts and tendencies or to become more depressed. If you or your caregiver notice any of these unwanted effects, tell your doctor right away.

acamprosate may cause some people to become drowsy, dizzy, or less alert than they are normally. Make sure you know how you react to acamprosate before you drive, use machines, or do anything else that could be dangerous if you are dizzy or are not alert.

Indications and Usage for Acamprosate

Acamprosate calcium delayed-release tablets are indicated for the maintenance of abstinence from alcohol in patients with alcohol dependence who are abstinent at treatment initiation. Treatment with Acamprosate calcium delayed-release tablets should be part of a comprehensive management program that includes psychosocial support.

The efficacy of Acamprosate calcium delayed-release tablets in promoting abstinence has not been demonstrated in subjects who have not undergone detoxification and not achieved alcohol abstinence prior to beginning Acamprosate calcium delayed-release tablets treatment. The efficacy of Acamprosate calcium delayed-release tablets in promoting abstinence from alcohol in polysubstance abusers has not been adequately assessed.


In all reported cases of acute overdosage with Acamprosate calcium (total reported doses of up to 56 grams of Acamprosate calcium), the only symptom that could be reasonably associated with Acamprosate calcium was diarrhea. Hypercalcemia has not been reported in cases of acute overdose. A risk of hypercalcemia should be considered in chronic overdosage only. Treatment of overdose should be symptomatic and supportive.

Clinical Studies

The efficacy of Acamprosate calcium in the maintenance of abstinence was supported by three clinical studies involving a total of 998 patients who were administered at least one dose of Acamprosate calcium or placebo as an adjunct to psychosocial therapy. Each study was a double-blind, placebo-controlled trial in alcohol-dependent patients who had undergone inpatient detoxification and were abstinent from alcohol on the day of randomization. Study durations ranged from 90 days to 360 days. Acamprosate calcium proved superior to placebo in maintaining abstinence, as indicated by a greater percentage of subjects being assessed as continuously abstinent throughout treatment.

In a fourth study, the efficacy of Acamprosate calcium was evaluated in alcoholics, including patients with a history of polysubstance abuse and patients who had not undergone detoxification and were not required to be abstinent at baseline. This study failed to demonstrate superiority of Acamprosate calcium over placebo.

Dosing Geriatric

Refer to adult dosing.

Acamprosate Food Interactions

Medications can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of acamprosate, there are no specific foods that you must exclude from your diet when receiving this medication.

Inform MD

Before taking acamprosate, tell your doctor about all of your medical conditions. Especially tell your doctor if you:

  • are allergic to acamprosate or to any of its ingredients, to any other medications, or sulfites.
  • are thinking of, or have ever thought of, harming or killing yourself or have ever tried to do so
  • use or have ever used street drugs or have overused prescription medications
  • have or have ever had depression or kidney disease
  • are pregnant or plan to become pregnant. If you become pregnant while taking acamprosate, call your doctor.
  • are breast-feeding
  • having surgery, including dental surgery

Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements.

Acamprosate and Lactation

Tell your doctor if you are breastfeeding or plan to breastfeed.

Acamprosate has been detected in human breast milk. Because of the possibility for adverse reactions in nursing infants from acamprosate, a choice should be made whether to stop nursing or to stop use of this medication. The importance of the drug to the mother should be considered.

Pregnancy & Lactation

Pregnancy Category: C

Lactation: Excretion in milk unknown; use with caution

Pregnancy Categories

A:Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

B:May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

C:Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

D:Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

X:Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

NA:Information not available.


Mechanism of Action

Not fully understood; may act by interacting with glutamate & GABA neurotransmitter systems

Does not cause alcohol aversion or a disulfiram-like reaction on ethanol ingestion


Protein Bound: Negligible

Vd: 1 L/kg

Peak PlasmaTime: 3-8 hr

Concentration: 350 ng/mL for a dose of 666 mg TID

Bioavailability: 11%, decreased by food

Metabolism: None

Excretion: Urine

Half-life: 20-33 hr

Usual Geriatric Dose for Alcohol Dependence

666 mg orally three times a day

Since geriatric patients may be more prone to a decrease in renal function, the manufacturer advises greater care in dose selection and close monitoring of renal function during therapy in this population.

Liver Dose Adjustments

Acamprosate is not metabolized by the liver and the pharmacokinetics of acamprosate are not altered in patients with mild to moderate hepatic impairment (groups A and B of the Child-Pugh classification). No adjustment of dosage is recommended in such patients.

Acamprosate is contraindicated in patients with severe hepatic impairment (Child-Pugh C).