How does this medication work? What will it do for me?

Acamprosate belongs to the family of medications called alcohol abstinence aids. It is used as part of a comprehensive alcohol dependence treatment program that includes counselling. Acamprosate is used by people who are alcohol-dependent to help them keep from drinking alcohol after they have stopped. It is thought to work by restoring the balance of chemicals in the brain that influence alcohol dependence.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. As well, some forms of this medication may not be used for all of the conditions discussed here. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

What form(s) does this medication come in?

Each delayed-release, enteric-coated, white, round-shaped tablet with "333" on one side, contains acamprosate calcium 333 mg. Nonmedicinal ingredients: anionic copolymer of methacrylic acid and acrylic acid ethyl ester, colloidal anhydrous silica, crospovidone, magnesium silicate, magnesium stearate, microcrystalline cellulose, propylene glycol, sodium starch glycolate, and talc.

How should I use this medication?

The recommended dose of acamprosate is 2 tablets 3 times daily. Lower doses may be needed for people with moderate kidney function impairment. Treatment is started as soon as possible after an alcohol-dependent person stops drinking alcohol and begins the comprehensive treatment program. The recommended treatment duration is 1 year.

Swallow this medication whole. Do not split, crush, or chew the tablets. This medication can be taken with or without food. If you eat 3 regular meals a day, taking this medication with your meals may help you remember to take it.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to take this medication exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Who should NOT take this medication?

Acamprosate should not be taken by anyone who:

  • is allergic to acamprosate or to any of the ingredients of this medication
  • is breast-feeding
  • has severe kidney function impairment

What side effects are possible with this medication?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • abdominal pain
  • appetite changes
  • change in sexual desire or abilities
  • diarrhea
  • dry mouth
  • gas
  • itchy skin
  • nausea
  • nervousness
  • prickling or tingling sensations
  • skin rash
  • trouble sleeping
  • vomiting
  • weakness
  • weight gain or loss

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

  • chest pain
  • joint pain
  • pounding, or fast heartbeat
  • symptoms of depression (e.g., losing interest in your usual activities, feeling sad)
  • thoughts or acts of self-harm

Stop taking the medication and seek immediate medical attention if any of the following occur:

  • signs of a severe allergic reaction (e.g., rash, itching, swelling, severe dizziness, trouble breathing)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Are there any other precautions or warnings for this medication?

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Depression and suicide: Although rare, people treated with acamprosate may be more likely to experience depression or commit suicide. If you have symptoms of depression (difficulty concentrating, reduced interest in activities, difficulty or increased sleeping, increased or decreased appetite, and feelings of guilt or hopelessness), contact your doctor immediately. If you have any suicidal thoughts or thoughts of harming yourself while taking this medication, seek immediate medical attention.

Impaired coordination: Although studies have not shown acamprosate to affect coordination, it is still recommended that people taking this medication be careful while driving or operating other machinery until they know how the medication affects them.

Impaired kidney function: People with moderate kidney function impairment may require lower doses of acamprosate and should be closely monitored by their doctor. People with severe kidney function impairment should not use this medication.

Treatment: Acamprosate does not eliminate or reduce the symptoms of alcohol withdrawal (symptoms experienced by alcohol-dependent people when they suddenly stop drinking alcohol). This medication also does not prevent the harmful effects of continuous alcohol abuse. Acamprosate should be used as part of a comprehensive alcohol dependence treatment program that includes counselling and support.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: It is not known if acamprosate passes into breast milk. This medication should not be used by breast-feeding women.

Children: The safety and effectiveness of using this medication have not been established for children under 18 years of age.

Seniors: The safety and effectiveness of this medication have not been established for seniors. Seniors who take acamprosate should be closely monitored by their doctor.

What other drugs could interact with this medication?

There may be an interaction between acamprosate and any of the following:

  • naltrexone

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.