Three medications are approved for alcohol use disorder in most Western markets: naltrexone, acamprosate, and disulfiram. They work in completely different ways, suit different patients, and produce different outcomes. There’s no single best answer; there’s the right answer for your specific situation. This article is part of our Naltrexone hub, the complete guide to using naltrexone for alcohol use disorder.
This article walks through what each medication does, who it suits, and why one might be a better fit for you than the others. None of this replaces a conversation with a prescriber, but going in informed makes that conversation substantially more useful.
# The short version
If you want one paragraph: naltrexone is the most-prescribed first-line option, suits people who want to drink less rather than stop entirely, and works by blunting the reward of alcohol. Acamprosate suits people who have already stopped drinking and want help staying stopped, by stabilising glutamate and GABA imbalances during early recovery. Disulfiram is for people who want a hard external commitment to abstinence, and works by making any drink immediately and unpleasantly toxic. Most prescribers start with naltrexone if there’s no reason not to.
The longer version is below.
# Naltrexone (Revia, Vivitrol)
What it does: Blocks mu-opioid receptors in the brain. When you drink alcohol while it’s active, the dopamine reward you’d normally get from drinking is partially or fully suppressed. Over time, drinking feels less rewarding, and the underlying urge to drink fades.
Two main protocols:
- Daily naltrexone: 50mg taken every day, regardless of whether you drink. Reduces overall drinking volume and prevents heavy days.
- The Sinclair Method (TSM): 50mg taken about an hour before drinking, only on drinking days. Goal is gradual extinction of the urge over months.
Suits: People who want to drink less rather than abstain. People with strong urges to drink heavily once they start (the “can’t stop at one” pattern). People who relapse on willpower alone but don’t want to commit to total abstinence yet.
Doesn’t suit: People taking opioid pain medications (absolute contraindication; they cancel out and naltrexone can trigger acute withdrawal). People with severe liver disease (use is risky above certain LFT thresholds). People who are already abstinent and stable; the medication has nothing to act on.
Side effects: Mild and transient for most. Nausea, headache, fatigue in the first 1-3 weeks. See our Naltrexone Side Effects guide for what’s normal.
Cost: Generic. £10-25/month UK, $4-50/month US, AUD $40-80/month Australia (much cheaper with PBS).
Evidence: Strong. Multiple RCTs since 1994. Effect size is modest but real (around 20-40% reduction in heavy drinking days for compliant patients).
# Acamprosate (Campral)
What it does: Modulates the glutamate/GABA balance in the brain. Heavy drinking causes neurochemical adaptation: glutamate goes up to compensate for alcohol’s depressant effect. When you stop drinking, the elevated glutamate is left unopposed, producing the anxiety, insomnia, and dysphoria of post-acute withdrawal that often last weeks. Acamprosate calms that residual hyperexcitability.
Protocol: 333mg tablets taken three times a day (roughly 2 grams total daily). Best started immediately after detox or after the last drink.
Suits: People who have already stopped drinking and want help staying stopped, especially in the first 3-6 months when post-acute withdrawal is at its worst. People with anxiety or insomnia in early recovery. People for whom naltrexone is contraindicated (e.g. opioid users, severe liver disease).
Doesn’t suit: People still drinking; acamprosate doesn’t reduce drinking, only helps you stay stopped. People with severe kidney disease (acamprosate is renally excreted). People who can’t reliably take medication three times a day.
Side effects: Mostly diarrhoea and mild GI upset. Lower side-effect burden than naltrexone for most people, partly because it doesn’t act on opioid pathways at all. Itchy skin, headaches, sexual side effects in a minority.
Cost: Generic. £20-40/month UK, $30-100/month US, PBS-subsidised in Australia.
Evidence: Strong, especially for relapse prevention in already-abstinent patients. The COMBINE trial (2006) found similar efficacy to naltrexone for different patient profiles. Most useful in first 6-12 months of abstinence; benefit fades after a year.
# Disulfiram (Antabuse)
What it does: Blocks the enzyme that processes acetaldehyde (the first metabolite of alcohol). Drink alcohol while disulfiram is active, and acetaldehyde accumulates rapidly, producing severe nausea, vomiting, flushing, headache, and a racing heart within 10-30 minutes. The reaction is unpleasant enough that most people on disulfiram simply don’t drink.
Protocol: 250mg daily, sometimes 500mg for higher tolerance. Active in the body for up to 14 days after the last dose, so a missed day or two doesn’t immediately remove protection.
Suits: People who want a hard external commitment to abstinence. People who have decided to stop and want a chemical guard against impulsive drinking. People in supervised treatment programs where adherence can be observed.
Doesn’t suit: People who haven’t decided to stop; the medication only works through the threat of consequences and offers no benefit if you’re going to drink anyway. People with cardiovascular disease (the disulfiram-alcohol reaction is dangerous at the heart). People with psychiatric conditions including severe depression (disulfiram has been associated with mood worsening in a minority). People who can’t be trusted to disclose accidental alcohol exposure (mouthwash, vinegar, certain cooking sauces, some over-the-counter medications all contain trace alcohol that can trigger reactions).
Side effects when not drinking: Generally minimal. Some patients report fatigue, mild peripheral neuropathy with long-term use, occasional liver enzyme rises (LFTs are monitored). Disulfiram-induced hepatitis is rare but real.
Side effects when drinking: This is the point. Severe nausea, vomiting, throbbing headache, sweating, flushing, racing heart, low blood pressure. Onset within 10-30 minutes; lasts 1-4 hours. In rare cases (especially with large drinks and underlying cardiovascular issues), the reaction can be fatal.
Cost: Generic. Cheap (~£10-20/month UK, $20-50/month US, PBS in Australia).
Evidence: Mixed. Disulfiram works extremely well for compliant patients. The challenge is that it requires daily commitment to abstinence, and most patients eventually skip a dose, then another, then drink. Effective only with reliable adherence; supervised disulfiram (taken under observation) has substantially better outcomes than self-administered.
# How to choose
The questions to ask yourself, roughly in this order:
1. Are you currently drinking, or have you stopped?
If you’re still drinking and want to either drink less or stop gradually: naltrexone. Either daily or via the Sinclair Method.
If you’ve stopped and want help staying stopped: acamprosate is often the first choice, particularly if you have anxiety or insomnia in early recovery. Naltrexone is also a reasonable option for staying stopped, especially if you have urges around specific triggers.
If you’ve stopped and want a hard chemical guard against impulsive drinking: disulfiram, with the caveats below.
2. Are you taking opioid medication, or might you need to?
If yes (chronic pain, post-surgery, addiction maintenance therapy with buprenorphine or methadone): naltrexone is contraindicated. Choose acamprosate or disulfiram.
3. Do you have liver, kidney, or cardiovascular issues?
Significant liver disease pushes you away from naltrexone (and to a lesser extent disulfiram). Significant kidney disease pushes you away from acamprosate. Significant cardiovascular disease is a hard caution against disulfiram because the disulfiram-alcohol reaction is genuinely dangerous in patients with arrhythmias or coronary disease.
4. Can you reliably take a medication three times a day?
Acamprosate’s tid (three times daily) dosing schedule is its biggest practical drawback. Patients who struggle with consistent multiple-daily-dose medications often do better on naltrexone (once daily or as-needed) or disulfiram (once daily).
5. How much external accountability do you want?
Disulfiram offers the most external accountability: there’s a 10-30 minute window between drinking and consequences, and the consequences are bad enough to deter most impulses. If you want that structure, you choose it deliberately. Most patients don’t.
# Combining medications
Some prescribers combine these, particularly naltrexone and acamprosate together. The COMBINE study tested this directly and found mixed results: combination wasn’t clearly better than either alone, but for some patient profiles it helped. There’s no safety issue with naltrexone + acamprosate together.
Disulfiram + naltrexone is rare but possible in highly-motivated patients who want both deterrent and reward suppression.
In practice, most patients are on one medication at a time. If one doesn’t work, you switch rather than stack.
# What about Vivitrol?
Vivitrol is the same molecule as oral naltrexone, given as a monthly intramuscular injection rather than a daily tablet. The mechanism is identical; the practical difference is adherence. Patients who struggle with daily medication often do better on monthly injections. We cover the comparison in Vivitrol vs Oral Naltrexone.
# What about Nalmefene?
Nalmefene is a closely-related opioid antagonist used in Europe (approved by the EMA for alcohol dependence under the brand Selincro). It’s similar to naltrexone but used as-needed before drinking, similar to TSM. Not approved in the US. We cover it in Nalmefene vs Naltrexone.
# How AlcoLog helps regardless of which medication you choose
AlcoLog’s Medications card supports all three: naltrexone, acamprosate, and disulfiram, plus four others (gabapentin, topiramate, nalmefene, and recovery supplements). Each medication has its own colour, its own redose timer (set in hours and minutes), and its own dose-logging via a 24-hour time picker. The last-24h dose list shows what you’ve taken at a glance.
Pro-tier location reminders fire when you arrive at a saved location: useful for naltrexone (the pub before drinking) or acamprosate (home, three times a day) or disulfiram (whenever you set the routine).
AlcoScore deliberately excludes medication use from its scoring. The app’s view: medication is a tool you choose to use, not a behaviour the app should grade you on. Your dose log informs you, not your score. Data stays on your device. CSV export of your last 10 sessions is free; unlimited export and PDF reports are on Pro for sharing with your prescriber.
