Naltrexone vs Vivitrol vs Antabuse: Two Medications, Not Three

What is the difference between naltrexone, Vivitrol, and Antabuse?

Naltrexone is the drug. Vivitrol is naltrexone in a monthly injection. Antabuse is the original brand name for disulfiram, a different drug that works in a different way. The Antabuse brand is listed as discontinued in the U.S., per FDA records, so a pharmacy today dispenses generic disulfiram. Naltrexone turns the volume down on drinking. Disulfiram makes a drink punish you.

Everything in the table comes from the FDA labels for Vivitrol, naltrexone tablets, and disulfiram, and from NIAAA. A third alcohol medication, acamprosate, is covered under alternatives below.

Is Vivitrol the same as naltrexone?

Yes. Same molecule, different container. The pill is taken every day at home. Vivitrol is 380 mg of naltrexone in microspheres, injected deep into the buttock muscle by a health care provider every four weeks, alternating sides. Its label says it blocks opioids for about 28 days.

The real difference is the daily decision. A pill can be skipped on the exact day it matters most. A shot already given cannot. That is most of the case for Vivitrol.

The trade-off is the injection site. The label warns of pain, hardness, or swelling, and in some cases tissue damage severe enough to need surgery. Tell the prescriber about any injection-site reaction that gets worse or has not improved two weeks after the shot.

Can you drink on naltrexone?

Drinking on naltrexone does not cause a reaction. The tablet label says plainly that naltrexone is not aversive therapy and does not cause a disulfiram-like reaction with alcohol.

That is the point. Naltrexone is meant to make drinking less rewarding, so one drink is less likely to become eight. It does not make a drink safe. NIAAA notes the pill can be started while a person is still drinking. SAMHSA adds that a person should not be physically dependent on alcohol when starting, so for anyone who is, prescribers usually wait until after detox. The shot has a stricter rule, below.

Does naltrexone make you sick?

Not when you drink. Nausea is the most common side effect, and it is not the same thing. In an open-label safety study of about 570 people taking the tablets for alcohol, new nausea showed up in 10 percent, headache in 7 percent, and dizziness and fatigue in 4 percent each. A 2023 JAMA meta-analysis of 118 trials found nausea about 1.7 times as common on naltrexone as on placebo.

Vivitrol and alcohol

Same answer: no reaction. The difference is at the start. Vivitrol’s label says the patient should be able to stop drinking as an outpatient before the first injection and should not be actively drinking when it is given. In the main trial, the extra benefit showed up in the small group (8 percent of patients) who had stopped drinking for the full week before the first shot; it was not evident in those still drinking when they started. In the label’s alcohol trials, nausea hit 33 percent on the 380 mg dose versus 11 percent on placebo. The patient guide says it usually eases within a few days and is less likely with later shots.

The label also says Vivitrol does not reduce alcohol withdrawal symptoms. If stopping drinking brings shakes, sweats, or worse, that is a withdrawal problem first and a medication question second.

What happens if you drink on Antabuse?

You get sick, by design. Disulfiram blocks the step that clears acetaldehyde, a toxic product of alcohol, so it builds up. The label lists what follows even small amounts of alcohol: flushing, throbbing in the head and neck, headache, trouble breathing, nausea, heavy vomiting, sweating, chest pain, a pounding or racing heart, low blood pressure, fainting, blurred vision, and confusion. Severe reactions can bring heart rhythm problems, heart attack, heart failure, seizures, collapse, and death. A reaction lasts 30 to 60 minutes, or several hours in severe cases, for as long as alcohol is in the blood.

Two rules follow from that. Disulfiram must never be given to someone who is intoxicated, and never without their full knowledge. It is not something to slip into a spouse’s coffee. And the first dose waits until the person has been alcohol-free for at least 12 hours.

Hidden alcohol, and the 14-day tail

The label warns patients to avoid alcohol in disguised forms: sauces, vinegars, cough mixtures, and even aftershave lotions and back rubs. It also says a reaction can happen with alcohol up to 14 days after the last disulfiram dose. Stopping the pill on Friday to drink on Saturday does not work, and it is dangerous to try. The label suggests carrying a card that says you take disulfiram and names a doctor to call.

Antabuse side effects without alcohol

• In the first two weeks, in a small number of people: drowsiness, tiredness, headache, acne-like rash, impotence, or a metallic or garlic-like aftertaste, which usually fade as treatment continues
• Liver injury, including hepatitis and liver failure that has led to transplant or death, sometimes after months of use; the label suggests liver tests at baseline and again in 10 to 14 days
• Nerve damage, including inflammation of the optic nerve (vision changes) and numbness or tingling in the hands and feet
• Psychotic reactions, mostly linked to high doses, certain drug combinations, or an underlying psychotic illness

The label rules disulfiram out for people with severe heart disease or psychosis, people allergic to thiuram compounds (used in rubber), and anyone taking metronidazole, paraldehyde, or alcohol-containing medicines. It also interacts with other drugs, including phenytoin, warfarin, and isoniazid, so the prescriber needs a full medication list. The label says it should not be given while breastfeeding and that its safety in pregnancy has not been established. Report yellow skin or eyes, dark urine, or ongoing nausea and fatigue to the prescriber right away.

The opioid rule: why naltrexone needs an opioid-free week first

Naltrexone is an opioid blocker. Given to someone with opioids still in their system, it knocks those opioids off the receptors at once. The result is precipitated withdrawal, sudden and severe. Both labels say it can be bad enough to need hospital care, in some cases intensive care.

• At least 7 to 10 days off short-acting opioids before the first dose, per both labels; SAMHSA says 10 to 14 days after long-acting ones
• People switching from buprenorphine or methadone can be at risk for up to two weeks
• Tramadol counts, and so do opioid cough medicines
• The rule applies to people starting naltrexone for alcohol, too

The labels say there is no completely reliable test for an adequate opioid-free period. A prescriber may use a urine screen or a naloxone challenge, but the most protective thing a patient can do is tell the truth about the last opioid, including a single pill. More on what this feels like in our guide to precipitated withdrawal.

While naltrexone is working, it also blocks opioid pain relievers and opioid cough and diarrhea medicines. The tablet label advises carrying identification that says you take naltrexone, and telling any doctor who treats you, including in an emergency, that you take it.

Overdose risk after stopping naltrexone

This is the most dangerous fact on the page. While naltrexone is active, opioid tolerance falls. When the pill is stopped, a dose is missed, or a Vivitrol shot wears off near the end of the month, a dose of opioids the person once handled can now stop their breathing. The Vivitrol label reports fatal overdoses in all three of those windows, and the tablet label reports them after people stopped treatment. Trying to push through the blockade with large amounts of opioids can also be fatal.

The Vivitrol label tells prescribers to discuss naloxone at every injection and to strongly consider prescribing it. Keep it in the house, and tell family about the lowered tolerance. Our naloxone guide for families covers how to get it in New Jersey.

Naloxone vs naltrexone

The names look alike, but the jobs are different. Naloxone (Narcan) is the rescue drug: a nasal spray or injection that quickly reverses an opioid overdose and restores breathing. It is not a treatment for addiction. Naltrexone is the prevention drug: taken daily or monthly to block opioids and reduce drinking. Naltrexone does nothing in an overdose emergency. Naloxone does.

Naltrexone vs Suboxone

For opioid use disorder, these sit on opposite sides. Buprenorphine, the drug in Suboxone, is a partial opioid agonist: it occupies the receptor and gives a weaker opioid signal. Naltrexone blocks the receptor and gives none. SAMHSA says buprenorphine is started once early withdrawal has begun, at least 12 to 24 hours after the last opioid. Naltrexone requires that withdrawal be finished, usually 7 or more days. Our Suboxone guide covers the buprenorphine side. The tablet label covers blocking the effects of opioids, but says the pill is of proven value only when there is some way to make sure it gets taken. Vivitrol is the form approved specifically to prevent relapse to opioid dependence after detox, and SAMHSA treats it as the naltrexone option for opioid use disorder.

Which one works best for alcohol?

The better question is which one a given person will actually take.

The 2023 JAMA meta-analysis, 118 trials and nearly 21,000 people, supported oral naltrexone at 50 mg a day and acamprosate as first-line medications, alongside counseling. To keep one person from returning to any drinking, about 18 people needed to take naltrexone, and 11 needed to take acamprosate. For preventing a return to heavy drinking, the number for naltrexone was 11. The monthly injection was linked to about five fewer drinking days a month. The tablet label calls the expected benefit a modest improvement on top of conventional treatment.

Disulfiram is harder to judge. A 2014 meta-analysis of 22 trials found it beat comparison groups only in open-label trials, where people knew they were taking it. Blinded trials showed no effect. For a drug that works through fear of the reaction, that fits: disulfiram works best when someone watches it get taken. The label makes the same point: a person who drinks on disulfiram with no reaction is presumed not to be taking it.

Few people with an alcohol use disorder get any of these medications. In 2024, only 2.4 percent of U.S. adults with a past-year alcohol use disorder received medication for it, according to federal survey data reported by NIAAA.

Alternatives to naltrexone

• Acamprosate. FDA-approved for alcohol. Two pills three times a day, started after withdrawal once the person has stopped drinking. NIAAA describes it as helping people stay abstinent by easing the anxiety, restlessness, and poor sleep of early sobriety.
• Disulfiram. For someone committed to not drinking at all, ideally with a supervised daily dose.
• Gabapentin or topiramate. Not FDA-approved for alcohol, but NIAAA notes that the American Psychiatric Association suggests them as second-line options for people who prefer them or did not respond to the approved medications.

Naltrexone and disulfiram together are not a standard combination. The naltrexone label says the safety of the pair is unknown and that combining two drugs that can injure the liver is not ordinarily recommended unless the benefits clearly outweigh the risks. If one medication does not work, NIAAA says trying another often helps.

How much does Vivitrol cost?

It depends almost entirely on coverage. Vivitrol is a brand-name monthly injection, and what you pay is set by your plan’s formulary, whether the shot is billed as a medical or a pharmacy benefit, your deductible and copay, and any fee for giving the injection. Ask for your own figure before the first dose.

Oral naltrexone and disulfiram are generic pills, and their prices vary by pharmacy and plan. Before the first dose, ask the plan and the prescriber’s office:

• Is the drug on my plan’s formulary, and at what tier?
• Is Vivitrol billed under my medical benefit or my pharmacy benefit?
• Does the prescriber’s office stock it, or order it from a specialty pharmacy?
• If I have commercial insurance, does the manufacturer offer copay help?

Why detox comes before any of these

None of them treats withdrawal. Vivitrol’s label says it does not reduce alcohol withdrawal. Disulfiram cannot start until 12 hours without a drink. And SAMHSA says that for alcohol, naltrexone is usually started after detox, in someone no longer physically dependent. If a person has been drinking daily and gets the shakes, sweats, or a racing heart when they stop, alcohol withdrawal can turn into seizures or delirium tremens. For someone who is physically dependent, the safe order is withdrawal first, managed by a clinician, then the medication. The alcohol withdrawal timeline shows when the dangerous hours fall, and our alcohol detox guide covers where to go in New Jersey. When you call a program, ask whether it can start naltrexone, acamprosate, or disulfiram before discharge or hand you to a prescriber who will.

For opioids, the same logic runs harder: naltrexone cannot start until opioid withdrawal is over. Our opioid detox guide covers that step, and our medication for addiction treatment guide compares naltrexone with buprenorphine and methadone.

In New Jersey

Any licensed prescriber can prescribe naltrexone, according to SAMHSA, and NIAAA notes that no special training is required for the three FDA-approved alcohol medications. A primary care doctor can start them. Fully insured New Jersey plans and the State Health Benefits and School Employees’ plans cannot require prior authorization for the first 180 days per plan year of in-network treatment your own physician, psychologist or psychiatrist finds medically necessary. Self-funded employer plans, Medicare and Medicaid are not covered by that rule. Our insurance guides go plan by plan. ReachNJ, the state treatment line, is at 1-844-732-2465.

Periscope Behavioral Health, which publishes this site, is opening a medical detox in Hammonton, Atlantic County, expected Summer 2027. For help independent of us, the state’s IME Addictions Access Center at 1-844-276-2777 screens NJ FamilyCare and uninsured residents and refers them to treatment. Until the Hammonton detox opens, the admissions line of our publisher, Periscope Behavioral Health, at (888) 313-3583, can talk through options in New Jersey and Florida, including facilities Periscope operates. What a plan covers depends on the plan and the facility’s network status.

Choosing between them

Start with opioids. If there is any opioid use in the picture, including a pain prescription or tramadol, naltrexone in either form needs an opioid-free start and leaves a lower tolerance behind it, and that has to be planned with the prescriber before anything else. If the problem is alcohol alone, the practical question is how the medication will get taken. Someone who skips pills on bad days may be a better fit for the monthly shot, a question to raise with the prescriber. Someone who wants a hard stop, and has a person willing to watch the daily dose, may choose disulfiram, knowing a drink can still make them sick up to two weeks after the last pill. Someone who wants neither can ask about acamprosate. Anyone who is pregnant or breastfeeding should raise it before starting any of them. And if the body is already dependent on alcohol or opioids, withdrawal comes first.