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What to avoid when taking naltrexone?

Medically reviewed by Leigh Ann Anderson, PharmD. Last updated on July 24, 2023.

Official answer


You should not use naltrexone treatment if:

  • You are receiving opioid (narcotic) analgesics.
  • If you are dependent (addicted) on opioids.
  • If you are in an acute opioid withdrawal or have any symptoms of opioid withdrawal.
  • If you have failed a naloxone challenge test or have a positive urine screen for opioids.
  • You have acute hepatitis or hepatic failure.
  • If you are allergic or have had a hypersensitivity reaction to naltrexone, polylactide-co-glycolide (PLG), or any other diluent or inactive ingredient in the product.

Tell your doctor or other health care provider of any recent use of opioids or any history of opioid dependence before starting naltrexone to avoid having an opioid withdrawal. Your doctor may require that you pass a naloxone challenge test and/or a urine screen for opioids prior to naltrexone use.

What is naltrexone used for?

  • Naltrexone is a pure opiate antagonist approved to treat patients with opioid use disorder (OUD) or alcohol use disorder, along with a medically-supervised behavior modification program.
  • Naltrexone itself will not cause narcotic-like effects or dependence.

Naltrexone blocks euphoric actions only (meaning it can't lead to addiction or a "high"). It also may block the "high'' feeling that may make you want to consume alcohol. Naltrexone is not a cure for addiction to opioids or alcohol.

It is available by prescription as a long-acting intramuscular injection (brand name: Vivitrol) or as a 50 mg oral tablet (a generic).

Naltrexone treatment is started after you are no longer dependent on opioids. Naltrexone use for either opioid use disorder or alcohol use disorder can lead to withdrawal symptoms if you are still using narcotics (opioids).

Naltrexone should not be used before you complete a medically-supervised opioid withdrawal lasting at least 7 to 14 days. This will help you to avoid an opioid withdrawal that may require hospitalization. If you have been using a more long-acting opioid such as methadone or buprenorphine, your detoxification period may need to be longer.

Which opioids should I avoid with naltrexone?

People using naltrexone should not:

  • use ANY opioid (for example: heroin, morphine, codeine, oxycodone, tramadol, hydrocodone or other prescription or illegal opioids)
  • use illicit drugs
  • drink alcohol
  • take CNS depressants such as sedatives, tranquilizers, or other drugs.

If you attempt to self-administer opioids, in small doses while on naltrexone, you will not perceive any effect. Naltrexone blocks the euphoric and sedative effects of the abused drug and prevents feelings of euphoria (“high”). However, using large doses of any opioid to try to bypass the opioid-blocking effect of naltrexone may lead to serious injury, overdose, coma, or death. You may be more sensitive to smaller doses of opioids once you stop using them, so taking any dose of an opioid can be dangerous.

What if I miss a dose of naltrexone?

  • Do not miss any dose of naltrexone as prescribed by your doctor. Your level of opioid tolerance will decrease while taking naltrexone.
  • Previous opioid dosages you used prior to naltrexone treatment may now have life-threatening consequences, including depressed or stopped breathing, circulatory collapse, and death.
  • You are also vulnerable to a potentially fatal overdose at the end of a dosing interval, after missing a dose, or after stopping treatment.

If you miss taking your oral naltrexone tablet, take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

If you miss your naltrexone injection appointment, contact your doctor’s office immediately to reschedule another appointment as soon as possible.

What if I take too much naltrexone?

Follow your doctor’s instruction exactly. The risk of liver injury is higher with single oral naltrexone doses above 50 mg.

  • Naltrexone will not cause euphoria or a "high". People do not typically abuse this drug to induce euphoria.
  • However, taking too much naltrexone may lead to severe liver (hepatic) injury.
  • Stop taking naltrexone and contact your doctor immediately if you develop stomach pain, white stools, dark urine, or yellowing in the whites of your eyes, all signs of liver injury.
  • If you have acute hepatitis or other severe liver disease, you should not use naltrexone.

Naltrexone use should be avoided in people who are currently using opioids, in people with certain types of liver disease or with chronic pain who rely on opioids for pain control.

Never give or sell naltrexone to anyone else, especially someone who is using opioids. Naltrexone will cause withdrawal symptoms in people who are using opioids.

Naltrexone Use and Alcohol Dependence

  • Naltrexone blocks the euphoric effects and feelings of intoxication from alcohol (the “buzz”). This allows people with alcohol use disorder to reduce their drinking behaviors enough to remain motivated to stay in treatment, avoid relapses, and take medications.
  • However, naltrexone will not prevent you from becoming impaired while drinking alcohol. Do not attempt to use naltrexone so that you can drive or perform other activities under the influence of alcohol.

For the treatment of alcohol dependence, you should not be actively drinking at the time you start naltrexone treatment. You should be able to abstain from alcohol in an outpatient setting (for example: at home, work and in your community) prior to initiation of treatment with naltrexone.

You should use naltrexone as part of a treatment program that includes counseling, support groups, and other behavioral methods as recommended by your doctor, for both alcohol use disorder and opioid use disorder.

Related questions

Who can use naltrexone?

  • Naltrexone is approved for use in adults 18 years of age and older.
  • Its use in patients younger than age 18 has not been approved by the FDA. It is not known if it is safe and effective in children under 18 years of age.

Naltrexone can be prescribed by any health care professional who is licensed to prescribe medications. It comes as a tablet (generic) and long-acting injection (Vivitrol). The tablets may be administered with or without food. Administration with food or after meals may help to lessen any stomach side effects.

Injectable naltrexone is only given by a health care provider. The injection will be shipped directly to your doctor and you will receive the injection at their office.

Do not attempt to give yourself an injection of naltrexone. Injectable naltrexone has been associated with serious injection site problems and skin reactions. If you experience any of these reactions after a naltrexone injection, contact your doctor immediately

  • Intense pain
  • Blisters
  • The area feels hard
  • Open wound
  • Large areas of swelling
  • Dark scab
  • Lumps

Tell your doctor if you have kidney (renal) disease before you start naltrexone treatment. Extra caution may be needed when you receive naltrexone.

If you have bleeding problems, low blood platelets, or a lung condition, tell your doctor before you start naltrexone treatment.

Naltrexone can cause depression in some patients. Tell your doctor if you have a history of depression, attempted suicide, or other mental health disorders before you start naltrexone treatment. Tell your family members or other people close to you that you are taking naltrexone. They should call a doctor right away if you become depressed or experience symptoms of depression.

Do not drive, operate heavy machinery or perform any dangerous activities until you know how naltrexone will affect you. Naltrexone may cause dizziness and drowsiness and affect your ability to drive or operate machinery. Do not drive or perform any kind of hazardous tasks if naltrexone causes you any dizziness or other dangerous side effects.

You should not use naltrexone if you are allergic to the drug, any vehicle or any inactive ingredients in the medication. Tell your doctor if you have ever had an allergic reaction to this medicine or any other substance.

If you are pregnant, breastfeeding or planning a pregnancy, be sure to tell your doctor before you start naltrexone treatment.

Is naltrexone the same as naloxone?

  • No. Be careful not to confuse the name naltrexone with naloxone (brand name examples: Narcan, Evzio).
  • Naloxone is used in an emergency opioid overdose to reverse effects such as slowed or stopped breathing.
  • Naloxone is not used in the treatment of opioid use disorder or alcohol use disorder.

Are there drug interactions with naltrexone?

There is the possibility of many different drug interactions with naltrexone. You should not start taking any new prescription medicine, over-the-counter (OTC) medication, vitamin, herbal or dietary supplement until you have had a drug interaction review completed by your doctor or pharmacist.

Learn More: Naltrexone Drug Interactions

Naltrexone will also block the effects of other opioid-containing medicines, such as cough and cold remedies and antidiarrheal preparations. While taking naltrexone, you may not benefit from these medicines or opioid analgesics. Always use a non-narcotic medicine to treat pain, diarrhea, or a cough. Ask your doctor about the best medicine to use.

Do I need a naltrexone identification card?

Yes, carry your naltrexone identification card with you at all times.

  • You should carry identification to alert medical personnel that you are taking naltrexone.
  • A naltrexone medication card may be obtained from your doctor and ensure that you can obtain adequate treatment in an emergency.
  • If you require medical treatment, be sure to tell the treating physician that you are receiving naltrexone therapy.

The naltrexone injection may cause an allergic-type of pneumonia. Patients should immediately notify their physician if they develop signs and symptoms of pneumonia, including trouble breathing, shortness-of-breath, coughing, or wheezing.

Learn More: Naltrexone Side Effects

Bottom line

  • Do NOT take opiates, including heroin or other prescription or illegal opiates while using naltrexone. Taking opiates with naltrexone increases your risk for an overdose, coma and death.
  • Do not use naltrexone if you are dependent on opioids or if you are experiencing opioid withdrawal symptoms.
  • Naltrexone should not be used before you complete a medically-supervised opioid withdrawal lasting at least 7 to 14 days.
  • Tell your doctor of any recent use of opioids or any history of opioid dependence before starting naltrexone to avoid having a possibly serious opioid withdrawal that may require hospitalization.

This is not all the information you need to know about naltrexone for safe and effective use. Review the full naltrexone prescribing information here, and discuss this drug with your doctor or other health care provider.

  • Patient Counseling Tool - Vivitrol (naltrexone for extended-release injectable suspension). FDA. Accessed August 3, 2020 at
  • Naltrexone Monograph. Accessed August 2, 2020 at
  • Sullivan MA, Bisaga A, Pavlicova M, et al. A Randomized Trial Comparing Extended-Release Injectable Suspension and Oral Naltrexone, Both Combined With Behavioral Therapy, for the Treatment of Opioid Use Disorder. Am J Psychiatry. 2019;176(2):129-137. doi:10.1176/appi.ajp.2018.17070732
  • Vivitrol (naltrexone for extended-release injectable suspension) intramuscular. Accessed August 2, 2020 at

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