Oral Naltrexone for Alcohol Use Disorder

Considering Naltrexone to Help Reduce or Stop Drinking

You may be looking for help cutting back on alcohol or staying stopped. Oral naltrexone is a prescription tablet that, with counseling and support, can help some people reduce drinking or maintain abstinence, meaning not drinking alcohol.^[1][2]

Alcohol use disorder (AUD) involves difficulty stopping or controlling alcohol use despite harmful consequences. It is a medical condition with evidence-based treatments, not a character flaw.^[3]

Alcohol Withdrawal Needs Separate Medical Care

Naltrexone does not prevent or relieve acute alcohol withdrawal, the symptoms that can occur when someone stops drinking^[2]. Suddenly stopping after prolonged heavy drinking can cause potentially life-threatening withdrawal, including seizures. Seek medical help to plan a safe recovery; withdrawal care is a separate need from deciding whether naltrexone fits longer-term treatment^[4].

What Oral Naltrexone Is and How It Works

Naltrexone hydrochloride belongs to a class of medications called opioid antagonists: medicines that block opioid receptors, the sites where opioids attach to produce their effects^[2][5]. It is available as a 50 milligram (mg) tablet taken by mouth, typically once a day with or without food^[1][2].

An extended-release injectable form also exists, but oral tablets and injections have different treatment schedules and evidence.⁠^[5]

How naltrexone works in AUD is not fully understood. Preclinical research—research conducted before studies in people—suggests involvement of endogenous opioids, the body’s own opioid-like chemicals. Naltrexone competes for the same receptor sites and may block these chemicals’ effects^[1].

Clinical studies have shown reduced alcohol consumption^[1], and the patient-information resource MedlinePlus states that naltrexone works by decreasing alcohol craving^[2].

Naltrexone is not “aversive therapy.” Unlike disulfiram, which causes unpleasant symptoms when alcohol is consumed, naltrexone does not produce a sickness reaction if a person drinks^[1]. It is also not addictive, does not lead to physical or psychological dependence, and does not cause withdrawal symptoms when it is stopped^[1][5].

Naltrexone is approved in the United States for the treatment of alcohol dependence. The prescribing information uses the older terms “alcohol dependence” and “alcoholism” to describe the alcohol problems studied^[1].

Naltrexone is one of three Food and Drug Administration (FDA)-approved medications for AUD, alongside acamprosate and disulfiram⁠^[3][5]. Acamprosate helps maintain abstinence by reducing negative symptoms sometimes experienced when not drinking; disulfiram discourages drinking by causing unpleasant symptoms when alcohol is consumed^[3].

What Trials Show About Oral Naltrexone for Alcohol Use Disorder

Oral naltrexone was tested in outpatient trials using 50 mg once daily for 12 weeks alongside counseling, with support to help participants take the medication as prescribed. These trials were placebo-controlled, meaning they compared naltrexone with an inactive tablet, and double-blind, meaning neither participants nor researchers knew who received which treatment during the trial^[1].

In one trial of 104 alcohol-dependent patients, naltrexone was superior to placebo on several drinking measures: abstention rates—rates of not drinking—were 51% versus 23%, and relapse rates—rates of returning to drinking as defined in the study—were 31% versus 60%^[1].

In a second trial of 82 alcohol-dependent patients, the naltrexone group had lower relapse rates (21% vs. 41%), less alcohol craving, and fewer drinking days compared with placebo, although the labeling notes that these results depended on the specific analysis used^[1].

A larger safety study followed 865 individuals with alcoholism at multiple treatment sites. It was uncontrolled, meaning it had no comparison group. Participants included people with mental health conditions occurring alongside alcoholism, other substance use, other medications taken at the same time, and human immunodeficiency virus (HIV) disease, an infection that affects the immune system^[1].

The study found that the pattern of side effects appeared similar to that seen in opioid-dependent populations and that serious side effects were uncommon^[1]. Without a comparison group, it cannot establish how much naltrexone changed the risk of these events.

How Much Improvement Can Oral Naltrexone Offer?

The prescribing information describes a modest improvement in conventional treatment outcomes and notes that naltrexone did not help every patient. The medication may help some people, but it is not a cure and does not guarantee a particular outcome.^[1]

The oral naltrexone label describes benefit as part of a broader treatment plan that includes counseling and support.^[1][2]

The controlled trials studied a specific dose (50 mg daily), duration (12 weeks), and population: outpatients receiving psychosocial treatment, meaning counseling and social support^[1]. They excluded people with psychosis, which affects a person’s grasp of reality; dementia, which impairs memory and thinking; or secondary psychiatric diagnoses—additional diagnosed mental health conditions^[1]. Results may not apply identically to every person or setting.

Who Should Discuss Oral Naltrexone With a Clinician?

Quitting is strongly advised—and professional guidance is important—for people who have AUD or symptoms of it, have a health condition worsened by drinking, or are taking a medication that interacts with alcohol^[4]. Naltrexone is one option a clinician may discuss in that context.

Before taking naltrexone, a person should tell their clinician about^[2][1]:

• Any current or recent opioid use, including prescription pain medicines, cough or cold medicines containing opioids, methadone or buprenorphine (opioid medicines also used to treat opioid dependence), or street drugs^[2][1].
• Liver disease or hepatitis, past or present. Hepatitis means inflammation of the liver. Naltrexone is processed extensively by the liver, and drug exposure increases substantially in people with liver cirrhosis, a condition involving serious liver scarring^[1].
• Kidney disease—naltrexone and its main metabolite, a breakdown product of the drug, leave the body mainly through urine^[1].
• Depression, and any current or emerging thoughts of self-harm or suicide—MedlinePlus warns that people who overuse drugs or alcohol often become depressed and sometimes attempt self-harm, and receiving naltrexone does not decrease the risk of self-harm^[2].
• Pregnancy, plans to become pregnant, or breastfeeding—there are no adequate studies in pregnant women, and it is unknown whether naltrexone passes into human milk^[1].
• All other medications, vitamins, and supplements—formal studies of interactions with non-opioid drugs have not been performed, so caution is advised with medications taken at the same time^[1].

Naltrexone has not been established as safe for use in people younger than 18^[1][5].

Why Opioid Use Matters Before Starting Naltrexone

Opioid use is an important safety consideration. Naltrexone is contraindicated—meaning it should not be used—in people currently taking opioid analgesics (opioid pain medicines), physically dependent on opioids, or in acute opioid withdrawal^[1]. Physical dependence means the body has adapted to regular opioid use, so stopping or blocking opioid effects can cause withdrawal symptoms^[5].

How Naltrexone Can Trigger Sudden Opioid Withdrawal

Because naltrexone blocks opioid receptors, giving it to someone physically dependent on opioids can trigger sudden, severe withdrawal, called precipitated withdrawal. This may require hospitalization or intensive care^[1].

Symptoms have appeared within five minutes of ingestion and lasted up to 48 hours. They can include major fluid losses from vomiting and diarrhea, confusion, somnolence (drowsiness), and visual hallucinations (seeing things that are not there)^[1].

To reduce this risk, the label recommends an opioid-free interval of at least 7 to 10 days for patients previously dependent on short-acting opioids—opioids whose effects last a relatively short time. Patients transitioning from buprenorphine or methadone may remain vulnerable to precipitated withdrawal for as long as two weeks^[1]. A clinician should assess readiness rather than relying on elapsed time alone.

This concern also applies to people being treated primarily for AUD—precipitated opioid withdrawal has been observed in alcohol-dependent patients when the prescriber was unaware of additional opioid use^[1].

A clinician may use a naloxone challenge test, a medically supervised assessment of the response to an opioid-blocking medicine, to help assess readiness. No method is completely reliable^[1]. Patients should give an accurate account of their last opioid use, including opioid-containing cough, cold, diarrhea, or pain medicines^[1][2].

Opioid Overdose Risk After Stopping Naltrexone

After stopping naltrexone, a person who previously used opioids may have reduced tolerance, meaning greater sensitivity to doses they once used. This creates a risk of life-threatening opioid poisoning, including respiratory arrest—when breathing stops. Fatal outcomes have been reported^[1]. Patients should inform family members about this increased sensitivity^[1].

Planning Pain Relief While Taking Naltrexone

While taking naltrexone, opioid-containing pain medicines may not work as expected^[1][2]. Trying to overcome this blocking effect by taking larger amounts of opioids can cause serious injury, coma, or death^[2].

Tell doctors and dentists that you take naltrexone before medical treatment or surgery, so they can plan pain relief. Carrying medical identification that states you are taking naltrexone helps emergency providers plan safe care^[1][2].

Naltrexone Side Effects and Warning Signs

Common Side Effects Reported With Oral Naltrexone

An open-label safety study—one in which participants and researchers knew the treatment being given—included approximately 570 individuals with alcoholism receiving naltrexone. Newly reported adverse reactions in at least 2% were nausea (10%), headache (7%), dizziness (4%), nervousness (4%), fatigue (4%), insomnia or difficulty sleeping (3%), vomiting (3%), anxiety (2%), and somnolence or drowsiness (2%)^[1].

During the two controlled 12-week trials, five of 93 patients receiving 50 mg daily discontinued because of nausea^[1]. Other reported effects include stomach pain or cramping, diarrhea, constipation, loss of appetite, irritability, tearfulness, difficulty sleeping, muscle or joint pain, and rash^[2].

Naltrexone and Signs of Liver Injury

Naltrexone may cause liver damage when taken in large doses. At recommended doses, clinically significant liver injury is considered unlikely, but cases of hepatitis and liver dysfunction have been observed during clinical development and in postmarketing reports—reports made after the medicine became available for prescribing^[1][2].

In a study of obese subjects receiving 300 mg per day, 5 of 26 naltrexone recipients (19%) developed elevated liver enzymes after three to eight weeks, compared with 0 of 24 on placebo^[1]. Liver enzymes are proteins measured in blood tests; raised levels can signal liver irritation or injury.

The patients were generally without clinical symptoms, and enzyme levels returned to or toward baseline—the levels before treatment—within weeks among those with follow-up^[1].

Warning signs of liver problems include excessive tiredness, unusual bleeding or bruising, loss of appetite, pain in the upper right part of the stomach lasting more than a few days, light-colored bowel movements, dark urine, or yellowing of the skin or eyes^[2].

MedlinePlus advises people experiencing these symptoms to stop taking naltrexone and contact their clinician immediately^[2].

Depression and Suicide Risk During Naltrexone Treatment

Depression, suicidal ideation (thoughts of suicide), and suicide attempts have been reported after naltrexone became available for prescribing, specifically when used to treat opioid dependence. These are postmarketing reports, and no causal relationship with naltrexone has been demonstrated^[1].

Separately, for alcohol-treatment populations, the label reports new-onset depression rates ranging from 0–15% with naltrexone and 0–17% with placebo; suicide attempt or ideation ranged from 0–1% with naltrexone and 0–3% with placebo. These numerical ranges describe reported events, not proof that naltrexone caused or prevented them^[1].

MedlinePlus notes that people who overuse drugs or alcohol often become depressed and sometimes try to harm themselves^[2]. Family members and caregivers should watch for sadness, hopelessness, guilt, or thoughts of self-harm, and contact a clinician right away if these appear^[2][1].

In the United States, get immediate help for suicidal thoughts or urges to self-harm: call or text 988. Call 911 for a life-threatening emergency⁠^[6].

Other Naltrexone Symptoms That Need Immediate Medical Advice

Confusion, hallucinations, blurred vision, and severe vomiting or diarrhea should be reported to a clinician immediately^[2].

Planning Naltrexone Treatment and Follow-Up for Alcohol Use Disorder

How Counseling and Support Fit With Naltrexone Treatment

The prescribing information and patient-information sources describe naltrexone as part of a treatment program that includes counseling and support^[1][2]. The National Institute on Alcohol Abuse and Alcoholism (NIAAA) notes more broadly that AUD medications may be used alone or in combination with counseling^[3].

These statements have different scopes: the oral naltrexone label describes the treatment setting in which its benefit was demonstrated, while NIAAA outlines medication options across AUD treatment^[1][3].

Behavioral treatments help develop skills for changing drinking behavior. Examples include cognitive-behavioral therapy, which addresses thoughts and behaviors linked to drinking, and motivational enhancement, which helps strengthen motivation to change. Mutual-support groups provide peer support for people stopping or reducing their drinking^[3].

Factors associated with good outcomes in the clinical trials included the type, intensity, and duration of treatment; management of co-occurring conditions; use of community-based support groups; and taking the medication as prescribed^[1].

Questions to Ask Before Starting Oral Naltrexone

When evaluating whether oral naltrexone fits your situation, consider discussing:

• Your drinking pattern and goals. Are you aiming for abstinence or reduced drinking? A clinician can help determine which approach and which medication, if any, align with your goals^[4][3].
• Your full medication list. Include prescription drugs, over-the-counter medicines, vitamins, and supplements. Highlight any opioid-containing products^[2][1].
• Your medical history. Liver disease, kidney disease, depression, and pregnancy status all affect whether naltrexone is appropriate^[1].
• Co-occurring mental health conditions. Depression, anxiety, trauma-related disorders, and sleep disorders commonly accompany AUD and should be addressed alongside it^[3].
• What to do if you need pain treatment or surgery. Plan ahead so that emergency providers know about naltrexone^[1][2].

Monitoring Liver Function and Progress With Naltrexone

Clinicians may order laboratory tests to check the body’s response to naltrexone, particularly liver function^[2]. Keeping all follow-up appointments matters—for many people, continued contact with a treatment provider is described as critical for overcoming alcohol problems^[3]. Practitioners should also continue to monitor patients after naltrexone treatment ends^[5].

Responding to Setbacks in Alcohol Use Disorder Recovery

AUD is a chronic, relapsing condition—one that can persist over time and recur after improvement. Setbacks do not mean failure; they are common and can be learning opportunities^[3]. Medications can help deter drinking during high-risk periods, and behavioral therapies can help develop skills to avoid and overcome triggers, the situations or experiences that prompt drinking^[3].

NIAAA defines recovery as a process that includes both remission from AUD—no longer meeting the criteria for active AUD—and stopping heavy drinking. Recovery often includes improvements in physical health, mental health, and relationships^[3].

Find Help With Naltrexone and Alcohol Use Disorder Treatment

Use these resources to explore care and prepare questions for a provider.

1. Talk to a primary care provider. They can evaluate your drinking pattern, assess your overall health, discuss whether naltrexone or another medication may be appropriate, and refer you to specialty care if needed^[3].
2. Prepare an accurate medication and substance-use history. Include any opioid use, even occasional use of cough or pain medicines, so your clinician can assess safety^[1].
3. Explore counseling options. Naltrexone may be used with behavioral treatment. Ask about cognitive-behavioral therapy, motivational enhancement, or other evidence-based approaches^[3].
4. Use available navigation tools. The NIAAA Alcohol Treatment Navigator (alcoholtreatment.niaaa.nih.gov) offers a step-by-step process for finding qualified treatment providers^[3]. The Substance Abuse and Mental Health Services Administration (SAMHSA) National Helpline can be reached at 1-800-662-4357 for help finding substance-use services^[5].
5. Carry medical identification. If you start naltrexone, carry a card or wear identification alerting emergency personnel, so they can plan safe pain management and other care^[1][2].
6. Involve trusted people. Let family members or close friends know about your treatment so they can watch for warning signs—especially depression—and help in an emergency^[1][2].

When looking for alcohol treatment, ask a prospective provider whether medication assessment, counseling, and follow-up are available. Discuss how your health, medication history, and drinking goals affect the choice of treatment.^[3]