Three medications are approved by the FDA to treat alcohol use disorder: naltrexone, acamprosate, and disulfiram. Each works differently, and the best choice depends on whether you’re trying to reduce drinking, maintain abstinence after quitting, or create a physical deterrent against relapse. A few additional medications are prescribed off-label when these three aren’t effective or aren’t a good fit.
Naltrexone: Reduces the Urge to Drink
Naltrexone is often the first medication considered for alcohol use disorder. It works by blocking opioid receptors in the brain, which are part of the reward circuit that makes alcohol feel pleasurable. Normally, drinking triggers the release of endorphins that boost dopamine, reinforcing the desire to keep drinking. Naltrexone interrupts that loop. You can still drink on naltrexone, but the rewarding “buzz” is blunted, which over time reduces cravings and makes it easier to cut back or stop.
The oral form (brand name Revia) typically starts at a low dose for the first few days, then increases to a standard daily tablet. For people who have trouble remembering a daily pill, or when oral treatment isn’t working well enough, an injectable version called Vivitrol is available. It’s given as a single shot once a month, which removes the compliance issue entirely.
Naltrexone has a slightly larger effect on drinking outcomes than acamprosate, but it also comes with more side effects. The most common are headache, nausea, and fatigue. These tend to be mild and often improve after the first week or two. One important limitation: because naltrexone blocks opioid receptors, it cannot be used by anyone taking opioid pain medications or who is physically dependent on opioids. It would trigger immediate withdrawal symptoms.
Acamprosate: Stabilizes the Brain After Quitting
Acamprosate (brand name Campral) takes a different approach. It’s designed for people who have already stopped drinking and want to stay sober. Chronic alcohol use disrupts the balance between excitatory and inhibitory signaling in the brain. When you quit, the brain is left in an overexcited state, which can cause anxiety, restlessness, irritability, and insomnia for weeks or months. These symptoms are a major driver of relapse. Acamprosate helps calm that overexcitation by rebalancing the brain’s signaling systems, particularly the interplay between glutamate and GABA activity.
The standard dose is around 2,000 mg per day, split into three separate doses. That three-times-daily schedule is one of the practical downsides, since it’s easy to miss a dose. The upside is that acamprosate is processed through the kidneys rather than the liver, making it a safer option for people with liver damage, which is common among heavy drinkers. The most frequently reported side effect is temporary diarrhea, and serious adverse effects are rare.
Disulfiram: Creates a Physical Deterrent
Disulfiram (brand name Antabuse) is the oldest of the three and works on a completely different principle. Rather than reducing cravings or stabilizing brain chemistry, it makes drinking physically unpleasant. Disulfiram blocks an enzyme your body uses to break down alcohol. Normally, your liver converts alcohol into a toxic byproduct called acetaldehyde, then quickly breaks that down further into harmless substances. Disulfiram stops the second step, so acetaldehyde builds up in your blood.
If you drink even a small amount of alcohol while taking disulfiram, the result is a cluster of deeply uncomfortable symptoms: facial flushing, sweating, nausea and vomiting, rapid heartbeat, a drop in blood pressure, dizziness, and difficulty breathing. This reaction can begin within minutes and last for an hour or more. The knowledge that drinking will cause this reaction is meant to serve as a powerful psychological deterrent.
Disulfiram works best for people who are highly motivated to stay abstinent and want an extra layer of accountability. It’s less effective for those who simply stop taking it when they decide to drink. It also requires caution with any hidden sources of alcohol, including certain cough syrups, mouthwashes, and even some foods cooked with wine or beer.
Off-Label Medications
When the three approved options aren’t enough, some doctors prescribe medications developed for other conditions that have shown benefits for alcohol use disorder. The most commonly used off-label options are topiramate (an anti-seizure drug) and gabapentin (a nerve pain medication). Both have shown promise in reducing cravings and heavy drinking days in clinical trials, though they aren’t FDA-approved for this specific use.
Baclofen, a muscle relaxant, has attracted attention after a French physician publicly documented using high doses to eliminate his own alcohol cravings. Subsequent research has been mixed. A large trial of 320 patients found no significant difference in abstinence rates between baclofen and placebo, though it did show some reduction in overall alcohol consumption and a measurable anti-craving effect. Some people respond quickly to baclofen within days, while others need several weeks before noticing any benefit. The inconsistency in study results means baclofen remains controversial, and the doses that seem most effective are considerably higher than what’s typically prescribed for muscle spasms.
How Long Treatment Lasts
There’s no fixed timeline for how long you should stay on medication for alcohol use disorder. Clinical guidelines acknowledge that there isn’t strong evidence pointing to a specific optimal duration. In practice, most treatment courses last at least several months, and many people stay on medication for a year or longer. The decision to stop should factor in your history of relapse, how severe your drinking was before treatment, and how stable your recovery feels. Stopping medication too early is one of the more common reasons people relapse, particularly with acamprosate and naltrexone, where the protective effects end when you stop taking them.
Choosing the Right Medication
Your situation narrows the options more than you might expect. If you’re still drinking and want to gradually cut back, naltrexone is the most practical choice because it works whether or not you’re currently abstinent. If you’ve already stopped drinking and want to protect your sobriety, acamprosate is designed for exactly that phase. If you want a hard deterrent that removes the option of impulsive drinking, disulfiram provides that structure.
Liver health matters too. People with significant liver damage may not be good candidates for naltrexone or disulfiram, both of which are processed through the liver. Acamprosate, filtered by the kidneys instead, is generally the safer bet in that scenario. And if you take opioid medications for pain, naltrexone is off the table entirely.
All three medications work best when combined with some form of counseling or behavioral support. Medication addresses the biological side of alcohol use disorder, but the habits, triggers, and emotional patterns that drive drinking need their own attention. Most treatment programs use both together, and the evidence consistently shows better outcomes with the combination than with either approach alone.