Three medications carry FDA approval specifically for treating alcohol use disorder, yet fewer than one in ten people diagnosed with the condition ever receive a prescription for any of them. Naltrexone, acamprosate, and disulfiram each work through a different mechanism, and a growing list of off-label and experimental drugs is expanding the toolkit further. The gap between what these medications can do and how rarely they are prescribed is one of the more frustrating stories in modern addiction medicine.
The Three FDA-Approved Options
Naltrexone, acamprosate, and disulfiram have been available for years, and each takes a fundamentally different approach to the problem. Understanding what they actually do in the brain helps explain why one might work better than another for a given person.
Naltrexone blocks mu-opioid receptors, which are part of the brain’s reward circuitry. Alcohol triggers the release of endorphins that bind to these receptors, producing pleasure and reinforcing the desire to drink again. By occupying those receptors first, naltrexone dulls the rewarding “buzz” of alcohol, making it easier for people to stop after one drink or skip drinking altogether.1PubMed. Pharmacological mechanisms of naltrexone and acamprosate in the prevention of relapse in alcohol dependence It comes in a daily oral tablet and a once-monthly injection (marketed as Vivitrol). Naltrexone does not cause sickness if you drink on it; it simply makes drinking less satisfying.
Acamprosate works on a completely different system. When someone who has been drinking heavily stops, the brain’s excitatory glutamate signaling surges, producing anxiety, restlessness, insomnia, and cravings. Acamprosate calms that glutamate storm, likely by acting as an antagonist at certain glutamate receptor subtypes.2PubMed. Neuroprotective and abstinence-promoting effects of acamprosate: elucidating the mechanism of action The practical upshot is that it eases the protracted discomfort that follows early sobriety, which is exactly the period when relapse risk is highest. One downside: acamprosate requires taking two pills three times a day, a regimen that is easy to forget.
Disulfiram (brand name Antabuse) is the oldest of the three and works nothing like the other two. It blocks an enzyme called aldehyde dehydrogenase, which the liver uses to break down a toxic byproduct of alcohol metabolism.3PubMed. Role of disulfiram in the in vitro inhibition of rat liver mitochondrial aldehyde dehydrogenase If you drink while taking disulfiram, that toxic byproduct accumulates and produces flushing, nausea, vomiting, and a pounding headache. The aversive reaction is the whole point: disulfiram does not reduce cravings or adjust brain chemistry in the way naltrexone and acamprosate do. It works purely as a deterrent.4PubMed. Current Findings and Mechanisms of Action of Disulfiram in the Treatment of Alcohol Dependence That same mechanism also makes it dangerous if a patient drinks heavily despite being on the drug, which is why supervised dosing and strong motivation are considered important for its safe use.
Why So Few People Get Prescribed These Drugs
The numbers on prescribing rates are striking. In a large study of outpatient visits, only about 6% of patients with an alcohol use disorder diagnosis had a medication prescribed within a year, and among those who did get a prescription, the vast majority filled it. The bottleneck was not patients refusing the pills; it was clinicians not writing the prescriptions in the first place.5PubMed Central. Medications for Alcohol Use Disorder: Rates and Predictors of Prescription Order and Fill in Outpatient Settings Among patients with alcohol-associated liver disease, where reducing drinking is arguably most urgent, rates were even lower: roughly 2% of those with cirrhosis received an FDA-approved medication.6PubMed Central. Pharmacotherapy for Alcohol Use Disorder Is Underutilized Among Commercially Insured Adults With Alcohol-Associated Liver Disease
A systematic review of barriers identified three main clusters: clinicians feeling uncertain about the evidence or unsure how to prescribe; stigma and a philosophical resistance to treating addiction with medication; and practical access issues like formulary restrictions and cost.7Journal of Addiction Medicine. First-line Medications for the Outpatient Treatment of Alcohol Use Disorder: A Systematic Review of Perceived Barriers Many primary care doctors trained in an era when “alcoholism” was not framed as a medical condition at all, and some addiction counselors still view medication as a crutch that undermines the recovery process. The result is a treatment gap that has persisted for decades despite increasingly strong evidence.
Off-Label Medications With Growing Evidence
Several drugs developed for other conditions show real promise for alcohol use disorder. None have FDA approval for this indication yet, but clinicians prescribe them off-label, and the evidence base is expanding.
Gabapentin, originally an anti-seizure drug, has shown benefits for people in early recovery, particularly those struggling with insomnia and anxiety that follow heavy drinking.8PubMed Central. Gabapentin for the treatment of alcohol use disorder Sleep disruption and mood problems during early sobriety are common triggers for relapse, and gabapentin appears to help with both.9PubMed. The role of gabapentin in the management of alcohol withdrawal and dependence Exploratory research suggests it may work best for people with higher baseline anxiety and heavier drinking patterns, essentially those with the worst withdrawal-related symptoms.10PubMed Central. Identifying responders to gabapentin for the treatment of alcohol use disorder: an exploratory machine learning approach The main concern with gabapentin is its own misuse potential, especially in populations already prone to substance use, which has made some prescribers cautious.
Topiramate, another anti-seizure drug, has been tested in multiple trials. In one controlled study, patients who received low-dose topiramate alongside standard counseling had a lower relapse rate and stayed abstinent roughly twice as long as those who received counseling alone.11PubMed Central. Treatment of alcohol dependence with low-dose topiramate: an open-label controlled study Topiramate’s side effects, including cognitive dulling and tingling in the extremities, keep some patients from tolerating it, but the evidence for efficacy is strong enough that some guidelines include it as a reasonable option.
Baclofen occupies a special niche. It is the only medication tested in randomized trials specifically in patients with liver cirrhosis, a group for whom most other alcohol medications are either untested or contraindicated. Trials in cirrhotic patients found that baclofen promoted abstinence and was safe even in the context of advanced liver disease.12The Lancet. Baclofen in the treatment of alcohol-dependent patients with liver cirrhosis: a randomised, double-blind, placebo-controlled trial13PubMed Central. Baclofen for the Treatment of Alcohol Use Disorder in Patients With Liver Cirrhosis: 10 Years After the First Evidence For a patient whose liver is already badly damaged, baclofen may be the only pharmacological option with solid trial data behind it.
Experimental and Emerging Approaches
The most talked-about newcomer is semaglutide, a GLP-1 receptor agonist already well known as a diabetes and weight-loss drug. A randomized trial found that low-dose semaglutide reduced the amount of alcohol consumed in a lab setting, cut drinks per drinking day, and lowered weekly craving scores compared to placebo.14PubMed Central. Once-Weekly Semaglutide in Adults With Alcohol Use Disorder: A Randomized Clinical Trial A broader meta-analysis pooling data from multiple study designs found that GLP-1 receptor agonists were associated with reduced alcohol intake and lower relapse rates, with some of the strongest signals among people who also had diabetes or obesity.15eClinicalMedicine. Association between glucagon-like peptide-1 receptor agonists use and change in alcohol consumption: a systematic review and meta-analysis These are early days, and semaglutide is not approved for alcohol use disorder, but the biological rationale is interesting: GLP-1 receptors sit in brain areas involved in reward processing, and activating them appears to dampen the pleasure signals that drive compulsive consumption of alcohol, food, and possibly other substances.
Psilocybin-assisted therapy has also generated headlines. In a randomized trial, participants who received psilocybin alongside psychotherapy had roughly half as many heavy drinking days over eight months compared to an active placebo group.16JAMA Psychiatry. Percentage of Heavy Drinking Days Following Psilocybin-Assisted Psychotherapy vs Placebo in the Treatment of Adult Patients With Alcohol Use Disorder Additional trials are underway to replicate and extend these findings.17PubMed Central. Psilocybin-assisted therapy for reducing alcohol intake in patients with alcohol use disorder: protocol for a randomised, double-blinded, placebo-controlled 12-week clinical trial (The QUANTUM Trip Trial) The effect is thought to come from psilocybin’s ability to temporarily reorganize brain connectivity during a guided therapeutic session, loosening entrenched patterns of thought. This is not a take-home pill; it is a structured clinical experience that uses the drug as a catalyst for therapy, which makes it fundamentally different from every other medication on this list.
Varenicline, best known as a smoking cessation drug, has shown it can reduce alcohol consumption in heavy-drinking smokers. In one trial, people on varenicline drank significantly fewer drinks per week than those on placebo once drinking was initiated.18PubMed Central. Varenicline decreases alcohol consumption in heavy-drinking smokers A separate trial found that among men with both alcohol use disorder and cigarette dependence, varenicline reduced heavy drinking days and helped some achieve smoking abstinence, though the effect on drinking was not consistent in women.19JAMA Psychiatry. Effect of Varenicline Combined With Medical Management on Alcohol Use Disorder With Comorbid Cigarette Smoking For people who both drink heavily and smoke, varenicline offers the rare chance to address two problems with a single medication.
Matching the Right Medication to the Right Person
One of the most active areas of research is figuring out who responds best to which medication. The blunt reality is that no single alcohol medication works for everyone, and prescribing has historically been more trial-and-error than science. That is starting to change.
The most studied genetic predictor involves a variant in the mu-opioid receptor gene (OPRM1). A meta-analysis found that people carrying a specific version of this gene had about twice the odds of avoiding relapse on naltrexone compared to those without it.20PubMed. Association of µ-opioid receptor (OPRM1) gene polymorphism with response to naltrexone in alcohol dependence: a systematic review and meta-analysis However, at least one large VA study failed to replicate this finding, so the association is not considered settled.21PubMed. Opioid receptor gene (OPRM1, OPRK1, and OPRD1) variants and response to naltrexone treatment for alcohol dependence: results from the VA Cooperative Study Genetic testing for this variant is available but not standard practice.
A more practical approach asks a simpler question: why do you drink? Researchers have distinguished between “reward drinkers,” who drink mainly for the pleasurable effects, and “relief drinkers,” who drink to manage anxiety, stress, or other negative feelings. The logic is intuitive: naltrexone, which blocks the reward signal, should work best for reward drinkers, while acamprosate, which calms the glutamate-driven distress of withdrawal, should work best for relief drinkers. Studies using data from large clinical trials have partly validated this idea: people who primarily drink to relieve negative states did better on acamprosate than placebo, with large effect sizes.22PubMed Central. Reward and relief dimensions of temptation to drink: construct validity and role in predicting differential benefit from acamprosate and naltrexone The naltrexone side of the prediction has been harder to confirm cleanly in controlled data, though the high-reward/low-relief group does seem to benefit from both naltrexone and acamprosate.23PubMed Central. Examining a brief measure and observed cutoff scores to identify reward and relief drinking profiles: Psychometric properties and pharmacotherapy response A brief questionnaire to identify these drinking profiles has been developed and may eventually become a standard clinical tool for guiding prescribing decisions.24PubMed Central. Precision Medicine in Alcohol Dependence: A Controlled Trial Testing Pharmacotherapy Response Among Reward and Relief Drinking Phenotypes
Injectable Versus Oral Naltrexone
A practical consideration with naltrexone is the delivery method. The daily oral tablet requires consistent motivation every morning, and adherence tends to drop off over weeks. The once-monthly injection (extended-release naltrexone) sidesteps this problem entirely: one shot in a clinic and you are covered for about four weeks. In a study of veterans, the median time to relapse was roughly 150 days with the injection compared to about 50 days with oral naltrexone.25PubMed Central. Treatment outcomes of long-acting injectable naltrexone versus oral naltrexone in alcohol use disorder in veterans The injectable form costs more upfront, but the adherence advantage can make it the better value when relapse carries high medical or social costs.
Combining Naltrexone and Acamprosate
Because naltrexone and acamprosate target different brain systems, combining them makes pharmacological sense. A double-blind trial comparing the combination to each drug alone and to placebo found that the two-drug regimen beat placebo and outperformed acamprosate alone in preventing relapse to heavy drinking, though it did not clearly outperform naltrexone alone.26Archives of General Psychiatry. Comparing and Combining Naltrexone and Acamprosate in Relapse Prevention of Alcoholism The benefit of the combination persisted even after the medications were stopped, suggesting the two drugs may reinforce each other’s effects during a critical early period of recovery.27Alcohol and Alcoholism. Combined Therapy: What Does Acamprosate and Naltrexone Combination Tell Us? Combining these two medications is considered safe and is sometimes done in practice, though it is not yet standard.
The Role of Therapy Alongside Medication
A common assumption is that medication alone is never enough and that therapy must always be layered on top. The evidence is actually more nuanced. A systematic review found that adding cognitive behavioral therapy to a regimen of medication plus standard medical care did not show a clear additional benefit.28PubMed Central. Combined Pharmacotherapy and Cognitive Behavioral Therapy for Adults With Alcohol or Substance Use Disorders Meanwhile, a separate review found that adding medication to therapy improved outcomes about half the time, while adding therapy to medication improved outcomes about a third of the time.29Alcohol and Alcoholism. The Added Value of Pharmacotherapy to Cognitive Behavior Therapy And Vice Versa in the Treatment of Alcohol Use Disorders: A Systematic Review
What this means in practice is that you should not let the perfect be the enemy of the good. If someone is willing to take medication but cannot access weekly therapy, the medication alone is still a meaningful intervention. And if someone is engaged in counseling, adding medication to their plan is likely to improve their odds. The idea that both components must be in place before either one is worth doing has kept people from getting help they could have received.
Withdrawal Management Is a Separate Problem
It is worth being clear that the medications discussed so far are for preventing relapse over weeks and months. Acute alcohol withdrawal is a different medical situation that requires different drugs. Benzodiazepines remain the mainstay for managing the potentially dangerous symptoms of acute withdrawal, including seizures and delirium tremens. Long-acting benzodiazepines tend to provide a smoother withdrawal course, though no single one has been shown to be clearly superior to another. Patients with severe symptoms that do not respond to high doses may need additional medications such as phenobarbital.30SpringerLink / CNS Drugs. Inpatient management of acute alcohol withdrawal syndrome Once withdrawal is safely managed, the conversation about long-term relapse prevention medications can begin, but skipping the acute phase or attempting to manage severe withdrawal with naltrexone or acamprosate alone would be dangerous.
Pregnancy and Liver Disease
Two populations face especially complicated decisions around alcohol medications. For people with advanced liver disease, the choices narrow considerably. Naltrexone carries a warning about liver toxicity, and acamprosate has not been extensively studied in cirrhotic patients. As noted earlier, baclofen is the only drug with randomized trial evidence specifically in people with cirrhosis, which is why it occupies such an important niche despite being off-label.
During pregnancy, the situation is even more constrained. The known harms of heavy drinking during pregnancy are severe, yet there is almost no data on the safety of alcohol medications in pregnant women.31PubMed. Pharmacotherapies for the Treatment of Alcohol Use Disorders During Pregnancy: Time to Reconsider? A scoping review of both human and animal research concluded that the evidence is simply insufficient to make confident safety claims in either direction.32PubMed Central. The Safety of Alcohol Pharmacotherapies in Pregnancy: A Scoping Review of Human and Animal Research This creates a difficult clinical dilemma: for a pregnant person who cannot stop drinking, the harm from continued alcohol exposure is real and documented, but the tools to help them are essentially untested. In practice, behavioral interventions become the primary approach, with medication reserved for cases where the risk calculus overwhelmingly favors trying something pharmacological.
How Disulfiram Was Discovered
Disulfiram’s story is one of the more colorful accidents in pharmacology. The chemical was used in the rubber industry to speed up vulcanization. Workers exposed to it noticed they became violently ill whenever they drank alcohol after a shift. That observation, made by a researcher named E. E. Williams, eventually made its way into medicine.33Journal of Mental Health and Human Behaviour. Tracing the Journey of Disulfiram: From an Unintended Discovery to a Treatment Option for Alcoholism Danish researchers later tested the compound on themselves, confirmed the sickening reaction, and proposed it as a therapeutic tool. Disulfiram has been prescribed since the late 1940s, making it the longest-tenured alcohol medication still in use. Its mechanism was understood only in broad strokes for decades, with the detailed biochemistry of how it disables aldehyde dehydrogenase filled in much later. The drug’s persistence in clinical practice, despite never being glamorous or high-tech, reflects a basic truth about addiction treatment: sometimes the simplest deterrent works, as long as the patient is willing to use it.