How Long Does Acamprosate Take to Work? Pharmacists Answer 6 FAQs

Acamprosate is a prescription medication that treats alcohol use disorder (AUD). It works primarily by decreasing alcohol cravings. It can be a vital medication for people who take it. So if you or a loved one is prescribed acamprosate, knowing a few facts about it can help you get the most from it. 

Here, we’ll answer some frequently asked questions about acamprosate, including how long it takes to work and what happens if you drink alcohol while taking it.

1. How long does acamprosate take to work?

Acamprosate takes about 5 days to start working. This means that you’ll need to take your doses regularly for at least 5 days before you start getting the full benefits. After these initial days, you’ll need to take acamprosate consistently to continue benefiting from it.

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How long acamprosate takes to work is different from the amount of time it takes acamprosate to be absorbed. Your body absorbs each acamprosate dose in just a few hours. But it takes about 5 days for acamprosate to reach steady levels in your blood and significantly decrease your alcohol cravings.

2. How does acamprosate work?

Long-term alcohol use changes the balance of certain chemicals in the brain, including gamma-aminobutyric acid (GABA) and glutamate. It’s not clear how acamprosate works, but it might be by mimicking GABA. This lowers glutamate levels.

People with AUD have higher glutamate levels in the brain. High glutamate levels reinforce the desire to drink and can worsen alcohol withdrawal symptoms. So by decreasing glutamate, acamprosate can reduce cravings for alcohol. It may also help with alcohol withdrawal symptoms.

3. How long do you have to take acamprosate?

It depends on many factors, such as how severe your AUD is and what your goals are. There’s not an exact length of treatment that's right for everyone.

That said, some experts believe that you should take acamprosate at least 6 months. This may increase your chances of maintaining sobriety. And in some cases, your prescriber may recommend you take it for longer. Although long-term acamprosate use (greater than one year) hasn’t been well studied, it appears to be well-tolerated in most people.

4. What happens if you drink while taking acamprosate?

If you start drinking alcohol again while taking acamprosate, you can continue taking acamprosate. Alcohol and acamprosate don’t cause a negative interaction in your body. But contact your prescriber about what to do next. 

Relapse is often a part of the recovery process. It doesn’t mean you failed your treatment. Your healthcare team can talk with you about how to avoid triggers and strengthen your recovery program if you’ve relapsed.

5. How does acamprosate compare to other medications for alcohol use disorder?

Besides acamprosate, two other medications are FDA approved for AUD: naltrexone (Vivitrol) and disulfiram. 

Naltrexone and acamprosate are considered first-choice medications for AUD. Disulfiram is a “second-choice” medication, which means it’s usually only used if naltrexone or acamprosate doesn’t work, or if they can’t be used.

Acamprosate, naltrexone, and disulfiram all work in different ways and can cause different side effects. They’re also taken differently. For example, oral naltrexone and disulfiram are usually only taken once a day, while acamprosate is taken three times a day. There’s also an injectable version of naltrexone that’s administered once a month in your prescriber’s office. Acamprosate and disulfiram are only available as oral tablets. 

If you have certain health conditions, one medication may be better for you than another. For example, if you have severe liver damage, acamprosate may be a better option for you than naltrexone.

6. Is acamprosate safe to take?

Acamprosate is safe for most people, though side effects are possible. The most common side effects include nausea, diarrhea, and gas. Trouble sleeping and mood changes are also possible.

More seriously, depression and suicidal thoughts and behaviors have been associated with acamprosate. However, people with AUD have a higher risk of these symptoms in general. You may also be more likely to have mood changes if you start drinking alcohol again while taking acamprosate.

If you notice mood changes after starting acamprosate or at any other point during treatment, contact your healthcare team. Along with your family and friends, they can help support you if you relapse to drinking alcohol.

If you or someone you know is having thoughts of suicide, you’re not alone, and help is available. Call the National Suicide Prevention Lifeline at 988, or text HOME to 741-741 to reach the Crisis Text Line.

How to save on acamprosate

Acamprosate is available as a lower-cost generic. You can save up to 80% off the average retail price at certain pharmacies with a free GoodRx discount. With the discount, generic acamprosate’s price may be as low as $67.82.

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Written by:

Austin Ulrich, PharmD, BCACP

Austin Ulrich, PharmD, BCACP, is a board-certified ambulatory care clinical pharmacist. In his early career, he provided direct patient care in a variety of settings, including hospital and community pharmacies, and in a primary care clinic as a clinical pharmacist.

Edited by:

Amy B. Gragnolati, PharmD, BCPS

Amy Gragnolati, PharmD, BCPS, is a pharmacy editor for GoodRx. Amy currently holds her pharmacist license in Georgia and California.

Reviewed by:

Daphne Berryhill, RPh

Daphne Berryhill, RPh, has two decades of experience as a clinical pharmacist. She spent most of her career in the Chicago area practicing in-home infusion.

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