Two very different medications for alcohol use disorder — one blocks reward, one punishes drinking. Here's how they compare.
Educational Information Only
Not a substitute for medical advice. Always consult a licensed clinician.
If you have been researching medication options for alcohol use disorder, you have probably encountered two names: naltrexone and Antabuse (disulfiram). Both are FDA-approved for alcohol use disorder. Both are prescription medications. But they work in completely different ways — and the difference matters enormously for how they are used and who they are appropriate for.
Antabuse works through aversion. It blocks an enzyme called aldehyde dehydrogenase, which the body uses to break down acetaldehyde — a toxic byproduct of alcohol metabolism. When someone taking Antabuse drinks alcohol, acetaldehyde builds up rapidly in the bloodstream, causing an extremely unpleasant reaction: flushing, nausea, vomiting, rapid heartbeat, and in some cases, severe cardiovascular effects.
The idea is that the threat of this reaction will deter drinking. Antabuse does not reduce cravings or change the brain's relationship with alcohol — it simply makes drinking physically punishing.
The practical limitation of Antabuse is significant: it only works if you take it. Because the medication must be taken consistently, and because the consequences of drinking while on it are severe, adherence is often poor. Studies have found that Antabuse is most effective when it is supervised — meaning someone else observes the patient taking it daily.
Naltrexone works through a completely different mechanism. It is an opioid receptor antagonist — it binds to opioid receptors in the brain and blocks them. When you drink alcohol, the brain releases endorphins that bind to opioid receptors and produce a rewarding effect. Naltrexone blocks this process. You can still drink, but the brain does not receive the expected reward signal.
Unlike Antabuse, naltrexone does not cause a physical reaction when combined with alcohol. It does not make you sick. It simply reduces the rewarding effect of drinking.
In the context of the Sinclair Method, naltrexone is taken specifically before drinking — not as a daily medication. This targeted use is what produces pharmacological extinction: over time, the brain's association between drinking and reward is gradually weakened, leading to reduced cravings and reduced consumption.
| Feature | Naltrexone | Antabuse (Disulfiram) |
|---|---|---|
| Mechanism | Blocks alcohol reward (opioid antagonist) | Causes aversive reaction to alcohol |
| Can you drink while taking it? | Yes (central to Sinclair Method) | No — causes severe reaction |
| Reduces cravings? | Yes, over time with TSM protocol | No — does not affect cravings |
| Changes brain's relationship with alcohol? | Yes — pharmacological extinction | No |
| Requires abstinence? | No | Yes |
| FDA-approved for AUD? | Yes (1994) | Yes (1951) |
| Addictive? | No | No |
| Common side effects | Nausea, fatigue, headache (usually temporary) | Drowsiness, metallic taste, skin reactions |
| Liver considerations? | Yes — evaluate liver function before use | Yes — can cause liver toxicity |
The research generally favors naltrexone for most patients. Multiple large randomized controlled trials — including the landmark COMBINE study — have demonstrated that naltrexone reduces drinking days, reduces heavy drinking, and increases abstinence rates compared to placebo. The evidence base for disulfiram is more limited, and its effectiveness depends heavily on supervised administration.
A 2014 Cochrane review found that naltrexone significantly reduced the risk of returning to heavy drinking (relative risk 0.83) and reduced drinking days. Disulfiram showed benefit primarily in supervised settings.
Neither medication is appropriate for everyone. Key considerations include:
Both medications require a medical evaluation before prescribing. This site is for educational purposes only — always speak with a licensed clinician before making any decisions about medication.
Naltrexone and Antabuse represent two fundamentally different philosophies: one works with the brain's reward system to gradually reduce the drive to drink; the other works through punishment and deterrence. For most people, naltrexone — particularly when used in the Sinclair Method protocol — offers a more sustainable and scientifically grounded approach. But the right choice depends on individual circumstances, medical history, and goals.