Alcohol Use Disorder: The Evidence for Naltrexone and Acamprosate

The short answer#

Yes. Two non-controlled prescription medicines, naltrexone and acamprosate, have the strongest evidence for helping adults drink less or stop. Neither one is addictive, and neither is a controlled substance. In pooled trials, acamprosate helps roughly 1 in 12 people avoid a return to any drinking, and naltrexone helps roughly 1 in 12 avoid a return to heavy drinking. They work best paired with counseling, and a family doctor or internist can prescribe either one. Despite that track record, most people who could benefit are never offered them.

Key points#

• Naltrexone and acamprosate are approved by the FDA, are not controlled substances, and are not addictive; a primary care clinician can prescribe either.
• Naltrexone, a mu-opioid receptor blocker, blunts the reward from alcohol and is especially good at reducing heavy drinking, which fits people whose goal is to cut down rather than quit outright.
• Acamprosate, a glutamate system modulator, helps a destabilized brain re-settle and works best for people who have already stopped and want to stay stopped.
• In the largest meta-analysis, numbers needed to treat were about 12 for acamprosate (return to any drinking), 20 for naltrexone (return to any drinking), and 12 for naltrexone (return to heavy drinking).
• Head-to-head trials show no clear winner; the choice turns on the person's goal, their kidney and liver health, any opioid use, and how often they can take a pill.
• Medication plus brief counseling outperforms either alone, and abstinence is not required before starting.
• Disulfiram is a third approved medicine, but it is aversive, not first-line, and leans heavily on daily supervision to work.

Is there a medication for alcohol cravings, and why are these drugs so underused?#

There is, and in fact there are several. The gap is not the science; it is that the medicines rarely get offered. National treatment data reviewed by the federal Agency for Healthcare Research and Quality show that only a small fraction of people who meet criteria for alcohol use disorder ever receive an approved medication for it. Many people, and some clinicians, still picture alcohol treatment as counseling or a mutual-support group and nothing else. Prescriptions are a normal, evidence-based part of the toolkit.

Part of the reluctance comes from an old worry that you are swapping one drug for another. That worry does not apply here. Naltrexone and acamprosate are not controlled substances, carry no potential for misuse, and have no street value. You do not build tolerance to them, and stopping them does not cause a withdrawal syndrome of their own. They are closer in spirit to a blood-pressure pill than to a sedative: a tool that shifts the odds while a person does the harder work of changing a habit.

Two other realities keep expectations honest. First, these medicines lower risk; they do not switch off a craving like a light. Second, they perform best as one piece of a plan that usually includes counseling and follow-up. That combination, not a pill alone, is what the evidence supports. For context on what counts as risky drinking in the first place, our piece on Alcohol and Health Risks: What 'Moderate' Really Means lays out the current thresholds.

How does naltrexone work for alcohol?#

Alcohol triggers a release of the brain's own opioids, part of why a drink can feel rewarding. Naltrexone sits on the mu-opioid receptor and blocks that signal, so drinking delivers less of a lift. Over weeks, many people find that the pull toward a second and third drink loosens. MedlinePlus describes naltrexone plainly as an opiate antagonist that decreases the craving for alcohol.

The trial evidence is consistent. In the 2014 JAMA meta-analysis by Jonas and colleagues, which pooled dozens of randomized trials, oral naltrexone at 50 mg per day cut the return to heavy drinking with a number needed to treat of about 12. In practical terms, treat roughly 12 people and you prevent one of them from sliding back into heavy drinking who otherwise would have. Its number needed to treat for preventing a return to any drinking was about 20. Because naltrexone works on heavy drinking specifically, it is a strong fit for someone whose goal is to cut down rather than to hit zero.

Naltrexone comes in two forms: a daily tablet and an extended-release injection given once a month, which removes the need to remember a pill every day. There are two cautions worth knowing up front. It should not be combined with opioid use or started when opioids are needed for pain, because a mu-opioid blocker will both cancel the pain relief and risk precipitated withdrawal. It is also avoided in acute hepatitis or liver failure, so a clinician typically checks liver tests before and during treatment. Neither caution rules it out for most people, but both are reasons the prescribing decision belongs with a clinician who knows the full history.

What does the acamprosate evidence show?#

Acamprosate works on a different system. Prolonged heavy drinking pushes the brain's glutamate signaling out of balance, and when the alcohol is removed that imbalance shows up as restlessness, anxiety, poor sleep, and low mood. Acamprosate nudges that system back toward normal. As MedlinePlus puts it, it helps the brains of people who have drunk large amounts to work normally again, which is why it is used to help people who have already stopped stay stopped.

Its evidence is strongest for exactly that job. In the same JAMA meta-analysis, acamprosate prevented a return to any drinking with a number needed to treat of about 12. The AHRQ review that underpins those pooled numbers reached the same bottom line: acamprosate and oral naltrexone have the best and most consistent evidence among the options, and no head-to-head trial has shown one to be clearly superior. One practical difference is that acamprosate did not show a clear, separate benefit for heavy drinking the way naltrexone did, so its sweet spot is maintaining abstinence rather than trimming a heavy pattern.

The trade-off is the schedule and the kidneys. Acamprosate is usually taken as two tablets three times a day, which is more pills than a once-daily option, and it is cleared by the kidneys, so the dose is reduced in kidney impairment and it is not first-line when that impairment is more than mild. It also does not treat alcohol withdrawal, so it is not the drug to reach for in the first shaky days after a heavy drinker stops.

What helps cut down drinking, and where does counseling fit?#

Medication is one lever. The other, well supported on its own, is brief counseling. The US Preventive Services Task Force gives a B grade to screening adults for unhealthy alcohol use in primary care and offering short behavioral counseling to those who screen positive. Practically, that can be a handful of structured minutes: comparing a person's intake to recommended limits, setting a concrete goal, and following up. The same Task Force found the evidence insufficient to make the call for adolescents aged 12 to 17, a nuance we unpack in How a Few Minutes of Alcohol Counseling Earned a B Grade, and Why It Stops at Adolescents.

Put the two together and they reinforce each other. Counseling helps someone decide what to change and hold the plan; medication makes the change easier to sustain by taking some of the physiological pull off the table. In the trials, the medicines were tested alongside psychosocial support, not as a substitute for it, which is a good model for how to use them in real life. If drinking is tangled up with anxiety, depression, or another mental health concern, treating that alongside the drinking matters too, and our broader Mental and behavioral health section, along with When to Seek Help for a Mental Health Concern, can help you gauge when to reach out.

When to seek care#

Some situations call for prompt medical attention rather than a wait-and-see approach:

• Signs of alcohol withdrawal after cutting down or stopping: shaking hands, heavy sweating, a racing heart, nausea, or a rising sense of agitation. Withdrawal can escalate.
• Seizures, confusion, fever, or seeing or hearing things that are not there. These can signal severe withdrawal, a medical emergency that needs urgent care.
• Needing a drink in the morning to steady yourself, or drinking to avoid feeling sick. This pattern suggests physical dependence and a supervised plan is safer than quitting cold on your own.
• Thoughts of harming yourself, or drinking that is driving you toward a crisis. Contact a clinician or, in the US, call or text 988 for the Suicide and Crisis Lifeline.
• Yellowing skin or eyes, abdominal swelling, vomiting blood, or black stools, which point to serious alcohol-related organ damage.

Anyone who is physically dependent should not stop abruptly without medical guidance, because unmanaged withdrawal can be dangerous. A clinician can arrange a safe taper or supervised detox and then talk through whether naltrexone or acamprosate fits the goal.

Talk with a licensed clinician about your own situation and before starting or stopping any medication.