Naltrexone (ReVia, Vivitrol) Side Effects, Dosage and Cost

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About Naltrexone

Naltrexone is a medication commonly used to help treat alcohol or opioid dependence. 1 When used safely, it can help people remain abstinent by blunting the pleasurable sensations of these substances, as well as by reducing cravings for them.

This article answers common questions about naltrexone, including:

  • How does it work?
  • What are the side effects?
  • How is naltrexone administered?
  • Does it interact with foods or other medications?
  • How much does it cost?
  • Is it effective?

What Is Naltrexone?

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Naltrexone is a medication approved by the Food and Drug Administration (FDA) for the treatment of alcohol and opioid dependence. 2 The National Institute for Health and Care Excellence recommends naltrexone for people who are fully detoxed from alcohol or opioids and are highly motivated to remain abstinent. 1 Naltrexone is also sometimes used off-label to treat opioid and nicotine withdrawal as well. 2

Although naltrexone is a helpful medication, it is not a cure for alcohol or opioid dependence. 4 To be effective, naltrexone must be combined with other psychosocial therapies such as cognitive behavioral therapy or motivational interviewing, 5 or with a 12-step program such as Alcoholics Anonymous or Narcotics Anonymous.

How Does It Work?

Naltrexone falls into a class of medications known as mu-opioid receptor antagonists. 2 Signaling within the brain as well as between the brain and body takes place with the aid of neurotransmitters. These chemicals are released from specialized cells throughout the nervous system and exert their effects by binding to different receptors. When opioid-type neurotransmitters (e.g., endorphins) bind with the mu-receptor, a signal is sent that alters pain perception. In a dose-dependent manner, this molecular interaction may trigger additional signaling that leads to an accompanying pleasurable, relaxing or euphoric sensation.

You are teaching your brain that alcohol and opioids are no longer rewarding.

Naltrexone works by blocking these mu-opioid receptors so that other substances cannot attach to them. 1 When the mu-opioid receptors are blocked, these signaling mechanisms are altered. The perception of pleasure that might otherwise accompany the use alcohol or opioids is muted, as is the chemical reinforcement of their continued use.3

If you use naltrexone over a period of time, you are actually teaching your brain that alcohol and opioids are no longer rewarding.1 This, in turn, helps to reduce cravings and prevent a relapse. 1

Who Can Prescribe Naltrexone?

Physicians and nurse practitioners can prescribe naltrexone. 4 In some states, physician assistants and psychologists can prescribe it as well. 4

While your primary care provider is able to prescribe this medication, it is best to receive expert care from an addiction medicine specialist – namely a psychiatrist or a psychiatric nurse practitioner at either a psychiatric or an addiction clinic.4

Naltrexone should only be taken under the direct supervision of a healthcare provider.

Naltrexone Side Effects

Woman holding neck and head due to naltrexone side effects

Common side effects of naltrexone include:

  • Abdominal pain and cramps.
  • Anxiety.
  • Headache.
  • Joint and muscle pains.
  • Nausea and vomiting.
  • Sleep problems.
  • Tiredness.1

Less common side effects include:

  • Chills.
  • Delayed ejaculation.
  • Depression and irritability.
  • Diarrhea or constipation.
  • Dizziness.
  • Feeling energetic.
  • Loss of appetite.
  • Skin rashes.
  • Thirst. 1

Some people have experienced suicidal ideation while taking naltrexone. 1 People with a history of suicidal thinking may be at increased risk of this side effect. 1 If you begin to feel down, depressed or hopeless, speak with your healthcare provider.

Allergic Reactions

As with any new medication, you are at risk of developing an allergic reaction to naltrexone. 1

Symptoms of an allergic reaction include:

  • Sudden, raised red spots on your body.
  • Itching.
  • Stomach pain.
  • Nausea.
  • Feeling lightheaded, weak, confused and restless.1
  • Vomiting.
  • Swelling of the throat, mouth, lips or tongue.
  • Difficulty breathing.

If you develop an allergic reaction, seek medical attention immediately and discontinue the medication.

Long-Term Effects

Large doses and long-term use of naltrexone can hurt your liver, especially when naltrexone is combined with alcohol. 1 Contact your healthcare provider if you develop any of the following symptoms, which might indicate liver damage:

  • Dark urine.
  • Excessive fatigue.
  • Light-colored bowel movements.
  • Loss of appetite.
  • Pain in the upper right area of the abdomen that lasts longer than several days.
  • Unusual bruising or bleeding. 1

How Is Naltrexone Administered?

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Naltrexone comes as a tablet or as a gluteal intramuscular injection. 2 You and your healthcare provider can discuss which form works best for you. Both forms of naltrexone will begin blocking the mu-opioid receptors in your brain shortly after the first dose. 2

Most courses of naltrexone therapy are carried out for a minimum of 3 months.4


The tablet form of naltrexone comes in 25 mg, 50 mg and 100 mg doses. 2 The usual starting dose of oral naltrexone is 50 mg per day. But this may range from 25 mg to 100 mg depending on your situation. 2

Often, healthcare providers will give you an initial dose of 25 mg to test your tolerance of the medication’s side effects and make sure that you do not have an allergic reaction to it. 1

If you miss a dose, wait until your next scheduled dose. Never take extra doses to make up for a missed dose. 2


Sometimes healthcare providers will prescribe a 380 mg once per month intramuscular injection of naltrexone. 2 This method can cause some discomfort at the injection site. However, you do not have to remember to take a tablet every day. 1 You will need to wear a warning bracelet because this form of the medication will make you insensitive to opioid analgesia in the event of an emergency. 1

If you miss a dose, reschedule your injection appointment as soon as possible.

Drug Interactions

Pharmacist consulting patient about naltrexone

Naltrexone blocks the effects of any opioid-containing drug or medication, which includes some cough and cold remedies, antidiarrheal preparations and opioid analgesics. 2 While taking naltrexone, avoid alcohol because it will greatly increase your risk of liver damage. 1

Before starting naltrexone, tell your healthcare provider if you are taking any of the following medications:

  • Droperidol.
  • Fentanyl.
  • Leflunomide.
  • Lomitapide.
  • Mipomersen.
  • Teriflunomide.2

Naltrexone can cause opioid withdrawal symptoms in those who are opioid-dependent. Therefore, you should be detoxed from opioids for at least 7 days before taking your first dose. 1 Be honest with your healthcare provider about your most recent use to ensure a safe experience. Some clinicians may use a urine drug screen or skin test to verify that you are detoxed before beginning naltrexone treatment. 4

Never use heroin after having recently taken naltrexone. The medication lowers a person’s tolerance to heroin, which increases the risk of death from just a small amount.1

If you believe you or someone you love is experiencing the effects of an overdose, call 911 immediately.

Naltrexone Cost

The cost of naltrexone differs by insurance type, but the tablet form is often covered.2

  • Oral form. The price of oral naltrexone usually varies from $25 to $60 per month.2
  • Injectable form. The injection form of naltrexone is significantly more expensive, usually ranging from $700 to $1,100 per month.2

Sometimes insurance companies will require your healthcare provider to submit a prior authorization before they will cover naltrexone. 4 A prior authorization requires you to meet certain criteria. For example, you might have to demonstrate that you are fully abstaining from alcohol and opioids and that you are also participating in psychosocial treatment. 4

How Effective Is It?

Naltrexone has proven effective in several studies.

Several studies have looked at the effectiveness of naltrexone. Overall, it has shown some success in helping people control their alcohol and opioid use.

  • Based on a 2010 systematic review, naltrexone appears to reduce heavy alcohol consumption and reduce drinking days in those suffering from alcohol dependence. 7
  • A 2013 study published in the Journal of the American Medical Association found that naltrexone can reduce alcohol use in people with comorbid post-traumatic stress disorder and alcohol dependence. 8
  • Another Cochrane Systematic Review in 2015 found that naltrexone reduced re-incarceration rates in people with a history of both opioid abuse and criminal activity. 10
  • A 2011 Cochrane Systemic Review concluded that oral naltrexone was no more effective than psychotherapy or buprenorphine in treating opioid dependence. 9 This study also found that oral naltrexone did not increase rates of abstinence from opioids following a full detoxification. 10

Frequently Asked Questions

Is Naltrexone Addictive?

Naltrexone is not physically or psychologically addictive. 1 It can reduce cravings for alcohol and opioids, but it should not interfere with other pleasurable experiences. 2

Can You Drink Alcohol While You’re Taking Naltrexone?

You should not drink alcohol when taking naltrexone. 1 Combining alcohol with naltrexone can damage your liver. 1

Can Naltrexone Get You High?

You will feel neither “high” nor “down” when taking this medication. 1 You will probably not notice much of an effect beyond mild side effects. 1

Find an Alcohol or Opioid Abuse Treatment Program

If you or someone you know needs more information about alcohol or opioid addiction treatment, please call us toll-free, 24 hours a day at 1-888-319-2606 Who Answers? . We can verify your insurance and determine treatment coverage.

If you do not have insurance, please call the Substance Abuse and Mental Health Services Administration’s (SAMHSA) national helpline at 1-888-319-2606 Who Answers? (HELP).


[1]. Chisholm-Burns, S., Schwinghammer, T., Wells, B., Malone, P., & DiPiro, J. (2013). Pharmacotherapy principles and practice (3rd ed.). New York, NY: McGraw-Hill Medical.

[2]. Stahl, S. M. (2014). Prescriber’s guide: Stahl’s essential psychopharmacology (5th ed.). New York: NY: Cambridge University Press.

[3]. Sadock, B. J., Sadock, V. A., & Ruiz, P. (2015). Synopsis of psychiatry (11th ed.). Philadelphia, PA: Wolters Kluwer.

[4]. Gabbard, G. O. (2014). Gabbard’s treatments of psychiatric disorders (5th ed.). Washington, DC: American Psychiatric Association.

[5]. Anton, R. F, Moak, D. H., Latham, P. Waid, L. R., Myrick, H., Voronin, & Woolson, R. (2005). Naltrexone combined with either cognitive behavioral or motivational enhancement therapy for alcohol dependence. Journal of Clinical Psychopharmacology. 25(4):349-357.

[6]. Jhanjee, S. (2014). Evidence based psychosocial interventions in substance abuse. Indian Journal of Psychological Medicine.36(2):112-118. doi: 10.4103/0253-7176.130960

[7]. Rosner, S., Hackl-Herrweth, A., Leucht, S., Vecchi, S., Srisurapanont, M., & Soyka, M. (2010). Opioid antagonists for alcohol dependence. Cochrane Database of Systematic Reviews.12:CD001867. doi: 10.1002/14651858.CD001867.pub2.

[8]. Foa, E. B., Yusko, D. A., McLean, C. P. Suvak, M. K., Bux, D. A., Oslin, D. & Volpicelli, J. (2013). Concurrent naltrexone and prolonged exposure therapy for patients with comorbid alcohol dependence and PTSD: a randomized clinical trial. JAMA. 310(5):488-495. doi: 10.1001/jama.2013.8268.

[9]. Minozzi, S., Amato, L. Vecchi, S., Davoli, M., Kirchmayer, U., & Verster, A. (2011). Oral naltrexone maintenance treatment for opioid dependence. Cochrane Database of Systematic Reviews. 4:CD001333. doi: 10.1002/14651858.CD001333.pub4.

[10]. Perry, A. E, Neilson, M., Martyn-St James, M. Glanville, J. M., Woodhouse, R., Godfrey, C., & Hewitt, C. (2015). Pharmacological interventions for drug-using offenders. Cochrane Database of Systematic Reviews. 6:CD010862. doi: 10.1002/14651858.CD010862.pub2.

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