Acamprosate (Campral)
Acamprosate (Campral) is a medication used after alcohol withdrawal to help you maintain abstinence. Its modest benefit, three-times-daily schedule, kidney limits, side effects, and fit with your recovery goals shape whether it is a practical option.
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Acamprosate Helps Protect the Ground You Have Already Gained
Stopping drinking and staying stopped are different challenges. Acamprosate is built for the second one. It helps people with alcohol use disorder maintain abstinence, which means not drinking alcohol, after they have stopped drinking. You may also see it called Campral, a brand name for acamprosate[1].
Thoughts of suicide? Call or text 988, any time.
What to do next:
- Tell your prescriber now. The medication label calls for monitoring and prompt reporting[2].
- Bring in someone you trust. The label specifically asks families and caregivers to watch for new depression or suicidal thinking[2].
- Do not change the medication on your own. Ask the person who prescribed it what to do.
- Its clearest role is maintaining abstinence. It is started after alcohol withdrawal, once you have stopped drinking[2].
- The benefit is real but modest. A federal systematic review found a 12% relative reduction in return to any drinking, with no measured reduction in return to heavy drinking[3].
- The routine matters. The usual schedule is two tablets, three times a day, and the pill burden can make adherence difficult[2][4].
Acamprosate is not a rescue medicine, a treatment for alcohol withdrawal or a promise that urges to drink will disappear. It is one tool for protecting abstinence while counseling, follow-up and practical recovery support address the rest[2].
Where Acamprosate Fits in Alcohol Treatment
The U.S. Food and Drug Administration label is specific: acamprosate is indicated for people who are already abstinent when treatment begins. Its effectiveness has not been demonstrated in people who started it without first completing withdrawal and reaching abstinence[2].
That boundary does not mean everyone needs the same kind of detox program. It means acamprosate itself will not treat or lessen withdrawal symptoms. Detoxification is the medically managed process of clearing alcohol while preventing or treating withdrawal complications. If you have not stopped drinking, ask a healthcare professional how to stop safely and review what alcohol detox may involve before treating acamprosate as the next step[2].
The label says to begin as soon as possible after the withdrawal period, once abstinence has been reached. A Department of Veterans Affairs patient guide describes the practical starting window as about three to four days after stopping alcohol, but your prescriber should set the timing for you[2][6].
How Well Acamprosate Works for Alcohol Use Disorder
A fair reading is neither “it barely works” nor “it keeps everyone sober.” Acamprosate produces a modest average benefit for maintaining abstinence, and that benefit varies across studies and settings.
A federal Agency for Healthcare Research and Quality review found that acamprosate reduced the likelihood of returning to any drinking by 12% relative to placebo, an inactive treatment used for comparison in a clinical trial[3]. A separate Cochrane review of 24 randomized controlled trials with 6,915 participants reported a relative risk (RR) of 0.86, with a 95% confidence interval of 0.81 to 0.91[7].
The reviews reported a number needed to treat (NNT) of 11 and 9.09, respectively—roughly one additional person avoiding any drinking for every 9 to 11 people treated under the pooled study conditions[3][7].
The federal review also found that acamprosate reduced the percentage of drinking days by an average of 8.3 percentage points[3]. It did not reduce the likelihood of returning to heavy drinking[3].
That 12% is a relative reduction, meaning a proportional change from the starting likelihood, not a promise that 12 additional people out of every 100 will remain abstinent[3]. The number-needed-to-treat estimates are pooled averages, not a guarantee that the same extra benefit applies in every setting or starting group.
Another analysis pooled individual records from 22 trials in 18 countries. Continuous abstinence was reported for 28% of people taking acamprosate and 19% taking placebo, a difference of about nine people per 100[1].
The U.S. Results Were Less Convincing
Geography matters here. In the federal review, four U.S.-based trials did not show a benefit for percentage of drinking days, while trials conducted outside the United States showed 11.2 percentage points fewer drinking days with acamprosate[3].
That does not prove acamprosate fails in the United States. It does mean the pooled international average should not be presented as though every U.S. patient can expect the same result. Differences in detoxification, pretreatment abstinence, treatment length, other medications, counseling and participant severity may help explain why trials disagreed[4].
What the Evidence Says About Women and Men
Women were a minority of the trial population, but they were not absent. The individual-patient analysis included 1,317 women and 4,794 men[1]. It found no difference between women and men in acamprosate efficacy, safety or tolerability[1].
That finding supports using the same evidence base for women and men. It does not answer every question about pregnancy, breastfeeding, older adults or people with multiple substance use conditions. The label says efficacy in people using multiple substances has not been adequately assessed[2].
Acamprosate and Naltrexone Solve Different Problems
The most useful comparison is not “which medication is stronger?” It is “which outcome are you asking the medication to support?” A meta-analysis of 64 randomized trials found that acamprosate had the larger effect on maintaining abstinence, while naltrexone had the larger effect on reducing heavy drinking and craving[5].
| Your situation or goal | What the evidence points toward | Why |
|---|---|---|
| You have stopped drinking and want to remain abstinent | Acamprosate may fit | Maintaining abstinence is its approved use and the outcome where it compared more favorably[2][5] |
| You are focused on reducing heavy drinking or craving | Ask about naltrexone | Naltrexone had the larger effect on those outcomes in the comparative meta-analysis[5] |
| You are still drinking or may be in withdrawal | Acamprosate is not the immediate treatment | It does not treat withdrawal, and effectiveness was not demonstrated without prior withdrawal and abstinence[2] |
| You take prescribed opioids or have significant liver impairment | Acamprosate may be considered | Federal guidance notes that it does not use opioid blockade and is not cleared by the liver[4] |
The comparison still belongs in a conversation about your health, goals and ability to follow the dosing schedule. Read more about naltrexone, disulfiram and other medications for alcohol use disorder before reducing the choice to a single “best” drug.
How Acamprosate May Work
The mechanism is not completely understood. The label describes a hypothesis involving glutamate, a chemical messenger that can increase brain-cell activity, and gamma-aminobutyric acid (GABA), a chemical messenger that generally calms that activity. Together, these systems help regulate the brain’s balance between excitation and inhibition after long-term alcohol exposure[2].
That is a working explanation, not proof that the medication “resets” or “repairs” the brain. The outcome evidence is more useful than a tidy mechanism story: acamprosate modestly improves abstinence-related outcomes for some people, under the right starting conditions.
How to Take Acamprosate
The usual dose is two delayed-release 333-milligram tablets, three times a day. Each dose totals 666 milligrams, and the full day totals six tablets or 1,998 milligrams[2].
You may take it with or without food. Clinical trials used dosing with meals, so linking each dose to breakfast, lunch and dinner can create a practical reminder if you regularly eat three meals[2].
If you miss a dose, take the next dose at its regular time. Do not double the next dose[6]. If you are unsure what to do after several missed doses, ask your pharmacist or prescriber.
When Should You Expect It to Work
The label says acamprosate reaches steady-state blood levels within about five days[2]. That pharmacology number is not a promise that you will feel a clear change on day five.
The evidence does not establish one precise day when a person should feel acamprosate “kick in.” Its benefit is measured over weeks and months through abstinence and drinking outcomes, not through an immediate sensation. Ask your prescriber what progress should look like and when the first follow-up should happen.
The Three-Times-a-Day Routine Is a Real Tradeoff
The Department of Veterans Affairs and Department of Defense guideline warns that three-times-daily dosing and the tablet size can make adherence difficult[4]. Real-world data show why that practical issue deserves more than a sentence in the fine print.
In one review of 715 veterans receiving medications for alcohol use disorder in South Carolina and Georgia, acamprosate was available from prescription fills on 44.7% of days over six months[8]. Only 19.4% of acamprosate treatment courses reached at least 80% medication availability[8].
Those numbers do not prove that every person took every pill they had, and the veteran population may not represent everyone. They do show that a difficult routine can erase part of a medication’s potential before biology ever gets a chance to matter.
That makes adherence support part of treatment, not evidence that you have failed. Ask for help building reminders into meals, work and sleep. If the schedule still does not fit, tell your prescriber; a plan you cannot carry is useful clinical information.
Your Kidney Function Determines the Dose
Acamprosate leaves the body through the kidneys. Your prescriber should review kidney function before treatment because the result can lower the dose or rule the medication out.
Creatinine clearance is measured in milliliters per minute (mL/min):
- 30 to 50 mL/min: the recommended starting dose is one 333-milligram tablet three times daily[2].
- 30 mL/min or below: acamprosate is contraindicated, meaning it should not be used[2].
It is also contraindicated if you have had a hypersensitivity reaction to acamprosate or one of the tablet’s ingredients[2].
Liver Disease Changes the Decision Differently
Acamprosate is not metabolized by the liver. The label says mild to moderate liver impairment does not alter its pharmacokinetics, meaning how the body handles a medication, and does not require a dosage adjustment[2]. Federal guidance says it may be considered when someone has significant liver damage or is taking prescribed opioids[4].
That is not a blanket safety guarantee for advanced liver disease. If you have cirrhosis, alcohol-associated hepatitis or abnormal liver tests, your care team should consider the full clinical picture. Learn more about alcohol-associated liver disease.
Side Effects and the Problems Most Likely to Change Treatment
The label lists diarrhea, nausea, gas, appetite loss, anxiety, depression, dizziness, dry mouth, insomnia, itching and sweating among events reported at least 3% of the time and more often than with placebo in controlled trials[2]. The list describes what was reported during treatment; it does not prove acamprosate caused every event.
The label specifically links diarrhea to stopping treatment. It led 2% of people taking acamprosate to discontinue, or about 20 per 1,000, compared with 0.7%, or about 7 per 1,000, taking placebo[2].
Across trials lasting six months or less, 8% stopped acamprosate because of an adverse event, or about 80 per 1,000, compared with 6%, or about 60 per 1,000, on placebo[2]. In studies longer than six months, the rate was 7%, or about 70 per 1,000, in both groups[2].
What the Label Can and Cannot Say About Weight
Both weight gain and weight loss appear among reported events in the label. People taking acamprosate with an antidepressant reported both changes more often than people taking either medication alone[2].
That does not establish a predictable weight effect for acamprosate by itself. If weight changes after treatment begins, bring the timing, amount of change, appetite changes and your other medications to the prescriber instead of assuming one cause.
Acamprosate Is Not an Anxiety Treatment
Acamprosate is approved to maintain abstinence, not to treat anxiety[2]. Anxiety was among the events reported more often than placebo in trials, but that does not establish that acamprosate caused anxiety in any one person.
If anxiety is part of early recovery or changes after starting the medication, tell your care team. Treating alcohol use disorder and treating an anxiety disorder may require different tools, even when the experiences overlap.
Depression and Suicidal Thoughts Need a Clear Plan
Events involving suicidal thoughts or behavior were uncommon in trials but occurred more often with acamprosate than placebo: 1.4% (about 14 per 1,000) versus 0.5% (about 5 per 1,000) in studies lasting six months or less, and 2.4% (about 24 per 1,000) versus 0.8% (about 8 per 1,000) in year-long studies[2].
Completed suicides occurred in 3 of 2,272 people taking acamprosate and 2 of 1,962 taking placebo[2]. Depression-coded events occurred at similar rates in the two groups, and the label found no consistent pattern connecting suicidality with the course of recovery[2].
The action is monitoring, not panic. Tell your prescriber about new or worsening depression or suicidal thinking, and ask family or another trusted person to speak up if they notice a change. If you are thinking about suicide, call or text 988 now.
Acamprosate Does Not Create Medication Dependence
The label lists no Drug Enforcement Administration schedule for acamprosate. It also reports no evidence of abuse or dependence and no medication-withdrawal symptoms at therapeutic doses[2].
It does not create an alcohol-aversion reaction like disulfiram[2]. Federal guidance also says it may be considered when someone takes prescribed opioids[4].
How Long Treatment May Continue
There is no single duration that fits everyone. A Department of Veterans Affairs patient guide says most people take acamprosate for at least six months and often longer[6]. The label includes exposure for up to one year, so treatment at that length is within the studied range[2].
Do not stop simply because you have been feeling steady. Decide with your prescriber what would support continued recovery, what side effects or life changes matter, and how you will know when a medication change makes sense.
A Return to Drinking Does Not Automatically End Treatment
The label says acamprosate should be maintained if drinking resumes and instructs patients to discuss renewed drinking with their physician[2]. One drink is not a reason to quietly throw away the medication or declare recovery over.
Contact your prescriber, explain what happened and revisit the plan. The return to drinking may change the support you need even when it does not change the medication immediately.
Medication Works Inside a Larger Recovery Plan
The label requires acamprosate to be part of a comprehensive program that includes psychosocial support[2]. That can include counseling, mutual-help or peer support, medication follow-up and practical help rebuilding daily life.
The medication’s job is narrow: improve the odds that abstinence holds. It cannot choose your supports, repair relationships, solve housing or work problems, or make every difficult day easy. Those needs are legitimate parts of treatment, not distractions from it.
Explore alcohol rehab and the broader alcohol use disorder guide for other parts of care.
Which Treatment Fits Your Situation
Acamprosate may be worth asking about if you have stopped drinking, want abstinence to continue, have kidney function that permits treatment and can build a workable three-times-daily routine. It may also be considered when prescribed opioids or liver impairment make other choices less suitable[4].
It is less likely to fit the immediate question if you are still in withdrawal, want a medication aimed primarily at reducing heavy drinking, have severe kidney impairment or know the six-tablet routine will not be workable without additional support.
Bring these questions to the appointment:
- What is my kidney function, and does it change my dose?
- Have I been abstinent long enough to start?
- Is my goal maintaining abstinence or reducing heavy drinking?
- What will help me take three doses consistently?
- When will we review side effects, mood and progress?
- What should I do if I drink again or miss several doses?
If you are ready to look for care, find treatment help can help you start. You do not have to solve every part of recovery before making the first call.
The next step doesn’t have to be a big one. You can find treatment now and get matched with someone who can help you find the right care and take the next step. Reaching out today is a real step forward — and one you can make right now.
Frequently asked questions
Are Campral and acamprosate the same medication?
Yes. Campral is a brand name used for acamprosate[1]. The active medication discussed here is acamprosate calcium, which is also available as a generic delayed-release tablet.
Do you have to stop drinking before starting acamprosate?
Yes. Acamprosate is indicated for people who are already abstinent when treatment begins, and its effectiveness has not been demonstrated in people who started without completing withdrawal and reaching abstinence[2]. It will not treat alcohol withdrawal.
How long does acamprosate take to work?
The label says blood levels reach a steady state within about five days, but that is not a proven five-day symptom timeline[2]. Trials measure abstinence and drinking outcomes over weeks and months, so ask your prescriber what progress should look like and when to review it.
What should you do if you miss an acamprosate dose?
Take the next dose at its regular time and do not double it[6]. If you have missed several doses or the three-times-daily routine is becoming hard to follow, contact your prescriber or pharmacist for a plan.
Does acamprosate cause weight gain?
The label records both weight gain and weight loss and notes that both were reported more often when acamprosate was taken with an antidepressant than when either medication was taken alone[2]. That does not establish a predictable weight effect from acamprosate by itself.
Does acamprosate help anxiety?
Acamprosate is approved to maintain abstinence, not to treat anxiety[2]. Anxiety was also reported among events that occurred more often than with placebo in clinical trials. If anxiety is part of early recovery or changes after you start treatment, discuss it directly with your care team.
Is acamprosate a controlled substance?
The prescribing label lists no Drug Enforcement Administration schedule. It also reports no evidence of abuse or dependence and no medication-withdrawal symptoms at therapeutic doses[2].
Is acamprosate or naltrexone better?
It depends on the outcome you need. A meta-analysis found that acamprosate had the larger effect on maintaining abstinence, while naltrexone had the larger effect on reducing heavy drinking and craving[5]. Your health, goals and ability to follow the dosing routine still matter.
How long do people take acamprosate?
A Department of Veterans Affairs patient guide says most people take it for at least six months and often longer[6]. The medication label includes treatment exposure for up to one year[2]. Your prescriber should decide duration with you rather than using one automatic stop date.
Should acamprosate be stopped after drinking again?
Do not stop it automatically. The label says treatment should be maintained if drinking resumes and instructs patients to discuss renewed drinking with their physician[2]. Contact your prescriber so the medication and recovery plan can be reviewed together.
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