The short answer
Acamprosate is a prescription medicine that helps people with alcohol dependence stay off alcohol once they've stopped drinking. It's thought to work by settling brain chemistry that's been disrupted by long-term drinking. The most common side effect is diarrhoea, which usually settles within days. It's PBS-subsidised for people aiming for abstinence, and it isn't suitable if your kidney function is reduced.
On this page
What is acamprosate?
Acamprosate is a prescription medicine used to help people with alcohol dependence stay alcohol-free after they've stopped drinking [1][2]. It was first approved in Australia in 1999 [3], and several brands are now available [4].
The Australian Guidelines for the Treatment of Alcohol Problems recommend acamprosate to help maintain abstinence in people with moderate to severe alcohol use disorder, with the highest grade of evidence (Level A) [1]. It isn't a treatment for alcohol withdrawal itself. It's started once withdrawal symptoms have settled [2].
How does acamprosate work?
Long-term heavy drinking causes chemical changes in the brain, and acamprosate acts on those changes [2]. It's thought to reduce drinking by acting on two chemical messengers, GABA (which calms brain activity) and glutamate (which excites it) [1]. In animal studies it reduced the surge in glutamate that happens during alcohol withdrawal, although researchers haven't confirmed exactly how it works in people [3].
A few practical points:
- It takes about one to two weeks to reach effective levels in the brain [1].
- It's linked to reduced cravings and higher rates of staying alcohol-free [5].
- It isn't an "aversive" drug. Drinking while on it won't make you sick [2][5].
Does acamprosate work?
The evidence shows a modest but real benefit for staying off alcohol:
- Cochrane review (24 trials, 6,915 people). Acamprosate reduced the risk of returning to any drinking compared with placebo (risk ratio 0.86). About 9 people needed to be treated for one extra person to stay alcohol-free [6]. It also increased the number of days without alcohol [6]. It didn't significantly reduce heavy drinking [6].
- 2023 JAMA meta-analysis (118 trials). For every 11 people treated with acamprosate, one fewer returned to any drinking [7].
Not every trial agrees. In the large US COMBINE trial of 1,383 people, acamprosate showed no significant effect on drinking compared with placebo, with or without counselling [8]. Overall, though, the Cochrane authors concluded acamprosate is an effective and safe way to support continuous abstinence after detox [6].
What are the side effects of acamprosate?
Acamprosate is usually well tolerated [1]. The main side effects listed in the Australian product information are [3]:
| How often | Side effects |
|---|---|
| Very common | Diarrhoea |
| Common | Stomach pain, nausea, vomiting, wind, itching, rash, lower sex drive, erection problems |
| Uncommon | Higher sex drive |
| Very rare | Allergic reactions, including hives, swelling and anaphylaxis |
In the Cochrane review, diarrhoea affected about 11 more people in every 100 on acamprosate than on placebo [6]. Gut side effects usually settle on their own within days [1], and they're rarely bad enough to stop treatment [5]. Less common effects include tingling and confusion [1].
If you notice swelling of your face, lips or tongue, or have trouble breathing, call 000.
Mood. Depression and suicidal thoughts are known to be linked with alcohol dependence, and the product information advises doctors to watch for them during treatment [3]. Let your GP know if your mood drops.
Stopping acamprosate doesn't cause a withdrawal syndrome [1].
Acamprosate and your kidneys
Most of a dose of acamprosate leaves the body through the kidneys [1], and how quickly it's cleared tracks closely with kidney function [3]. That's why your doctor checks kidney function (and liver function) with a blood test before you start [1].
The Australian product information lists renal insufficiency, defined as a serum creatinine above 120 micromol/L, as a reason not to use acamprosate [3]. If your kidney function is borderline, your doctor will talk through other options.
Liver disease is less of a barrier. The product information says liver problems don't change how the body handles acamprosate, and it's only contraindicated in severe liver failure (Child-Pugh C) [3].
Who is acamprosate suitable for?
Acamprosate may suit you if:
- your goal is to stop drinking. The PBS listing requires a comprehensive treatment program with the goal of maintaining abstinence [4], and acamprosate may work better for abstinence than for cutting down, although this hasn't been fully established [1]
- you have moderate to severe alcohol use disorder, are medically stable, and can stick to taking tablets through the day [1]
- you've finished withdrawal. Guidelines suggest starting 3 to 7 days after your last drink [1], although some services start it earlier, during detox [5]. Starting early hasn't been shown to improve outcomes [1].
It isn't suitable if you have reduced kidney function, severe liver failure, an allergy to acamprosate, or are pregnant or breastfeeding [3]. The product information also says its safety hasn't been established in people under 18 or over 65, and it isn't recommended for those groups [3].
Acamprosate has few drug interactions. Its calcium content may make tetracycline antibiotics less effective [1]. It doesn't block opioid medicines [5], which is a key difference from naltrexone.
A consultation doesn't guarantee a prescription. Your GP decides what's clinically appropriate.
Can you take acamprosate and naltrexone together?
Yes, they can be taken together [5], but the evidence for combining them is mixed:
- How they interact. Taking both raised acamprosate levels in the blood by about a quarter, which the product information judges to have limited clinical impact. Naltrexone levels weren't affected [3].
- Kiefer trial (160 people). All three treatments beat placebo. The combination had the lowest relapse rates, significantly better than placebo and acamprosate alone, but not significantly better than naltrexone alone [9].
- COMBINE trial (1,383 people). No combination of medicines did better than naltrexone alone when given with regular medical check-ins [8].
SA Health's drug and alcohol service notes there's some evidence for benefit of the combination over a single medicine [5]. Whether it makes sense for you is a decision for you and your doctor.
Acamprosate vs naltrexone
| Acamprosate | Naltrexone | |
|---|---|---|
| Best suited to | Staying alcohol-free [1] | Preventing a return to heavy drinking [10] |
| PBS treatment goal | Maintaining abstinence [4] | Maintaining abstinence or controlled consumption [11] |
| Prevents a return to any drinking | One extra person per 11 treated [7] | One extra person per 18 treated [7] |
| Prevents a return to heavy drinking | Not significant in Cochrane review [6] | One extra person per 11 treated [7] |
| Main side effect | Diarrhoea [7] | Nausea [7] |
| Opioid medicines | Doesn't block them [5] | Not suitable with opioids [10] |
For more detail, see our guide to naltrexone for alcohol.
What happens if you drink while taking acamprosate?
Acamprosate doesn't interact with alcohol, so drinking won't make you ill [2][5]. The consumer medicine information still advises against drinking, because even small amounts can undermine treatment [2]. If you lapse, Australian guidelines say to keep taking acamprosate and use relapse prevention strategies [1].
How long do you take acamprosate for?
Acamprosate is usually taken for at least 3 to 6 months, and the decision to continue depends on side effects, past relapses and your circumstances [1]. There's no proven benefit beyond 12 months [5]. Support to prevent relapse continues after the medication stops [1].
How does acamprosate fit with other support?
Medication is one part of the plan. Australian guidelines recommend cognitive behaviour therapy as a first-line psychological treatment for alcohol dependence, and say its benefit is enhanced when combined with medication [12]. Peer support programs such as Alcoholics Anonymous and SMART Recovery also help people stay alcohol-free [12]. You can call the National Alcohol and Other Drug Hotline on 1800 250 015 for advice and local services [10].
If you take an antidepressant as well, see our guide to antidepressants and alcohol.
When should you see a GP?
See a GP if you want to stop drinking, have tried before and relapsed, or get cravings or withdrawal symptoms when you cut back. If you drink heavily every day, don't stop suddenly without medical advice.
If you'd like to talk to a GP about your drinking, without judgement, you can request an appointment. Our GPs can refer you to a psychologist or psychiatrist when needed. Read more on our alcohol page.
If you're in crisis or thinking about suicide, call Lifeline on 13 11 14 or 000 in an emergency.
This page is general information, not medical advice.
Common questions
What are the most common side effects of acamprosate?
Does acamprosate reduce cravings?
Can I drink alcohol while taking acamprosate?
Is acamprosate safe for your kidneys?
How long does acamprosate take to work?
Is acamprosate on the PBS?
Yes. Acamprosate is PBS-listed for alcohol dependence as a streamlined authority, as part of a comprehensive treatment program with the goal of maintaining abstinence [4].
References
- Guidelines for the Treatment of Alcohol Problems (4th ed). Chapter 10: Acamprosate. Accessed November 2026. alcoholtreatmentguidelines.com.au/frontline-pharmacotherapy-tgaapprove
- Campral Consumer Medicine Information. Alphapharm Pty Ltd (Viatris). March 2024. medsinfo.com.au/consumer-information/document/Campral_CMI
- Campral (acamprosate calcium) Australian Product Information. Alphapharm Pty Ltd (Viatris). Revised July 2023. medsinfo.com.au/api/documents/Campral_PI?format=pdf
- Pharmaceutical Benefits Scheme. Acamprosate 333 mg enteric tablet (item 8357W), alcohol dependence, streamlined authority. Schedule effective 1 November 2026. pbs.gov.au/medicine/item/8357W
- SA Health, Drug and Alcohol Services South Australia. Acamprosate in alcohol dependence. April 2023. sahealth.sa.gov.au/wps/wcm/connect/b7823552-b611-44b2-b735-affbf96089c
- Rösner S, Hackl-Herrwerth A, Leucht S, et al. Acamprosate for alcohol dependence. Cochrane Database Syst Rev. 2010;(9):CD004332. pubmed.ncbi.nlm.nih.gov/20824837
- McPheeters M, O'Connor EA, Riley S, et al. Pharmacotherapy for alcohol use disorder: a systematic review and meta-analysis. JAMA. 2023;330(17):1653-1665. pubmed.ncbi.nlm.nih.gov/37934220
- Anton RF, O'Malley SS, Ciraulo DA, et al. Combined pharmacotherapies and behavioral interventions for alcohol dependence: the COMBINE study: a randomized controlled trial. JAMA. 2006;295(17):2003-17. pubmed.ncbi.nlm.nih.gov/16670409
- 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(1):92-9. pubmed.ncbi.nlm.nih.gov/12511176
- Alcohol and Drug Foundation. Naltrexone. Published 7 October 2026. Accessed November 2026. adf.org.au/drug-facts/naltrexone
- Pharmaceutical Benefits Scheme. Naltrexone 50 mg tablet (item 8370M), alcohol dependence, streamlined authority. Schedule effective 1 November 2026. pbs.gov.au/medicine/item/8370M
- Haber PS, Riordan BC, Winter DT, et al. New Australian guidelines for the treatment of alcohol problems: an overview of recommendations. Med J Aust. 2021;215(Suppl 7):S3-S32. pubmed.ncbi.nlm.nih.gov/34601742
Published by Mental Health Clinic. Last updated 6 November 2026. This page is general information only and isn’t a substitute for advice about your own situation. If you or someone else is in danger, call 000.