Once-A-Month Naltrexone Injection for Substance Use Disorders

Table of ContentsView AllTable of ContentsWhat Is Naltrexone Used to Treat?Monthly Injection vs. Daily PillBefore Taking NaltrexonePrecautionsHow to Take NaltrexoneNaltrexone Side EffectsHow Effective Is Naltrexone?

Table of ContentsView All

View All

Table of Contents

What Is Naltrexone Used to Treat?

Monthly Injection vs. Daily Pill

Before Taking Naltrexone

Precautions

How to Take Naltrexone

Naltrexone Side Effects

How Effective Is Naltrexone?

Naltrexone injection is a medication that is used in conjunction with other methods to treat both alcohol use disorder and opioid use disorder. The medication has become one of the most effective pharmaceutical treatments foralcohol use disorder.

It works to reduce the chemical effects that alcohol has on the brain, potentially leading to decreased cravings and alcohol use. It can also be effective in the treatment of opioid dependence.

At a Glance

Naltrexone can be prescribed for a few different uses. These include:

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Benefits of a Monthly Injection vs. Daily Pill

Naltrexone is available as both a daily pill and a monthly injection. While both medications are effective, there are some clear benefits to a long-lasting, once-a-month injection.

Daily Naltrexone Pill

For the treatment of alcohol use disorder, naltrexone was originally prescribed as a daily pill. Naltrexone in pill form—marketed as ReVia and Depade—is still widely used.

However, there is an inherent problem with the pill form of naltrexone: it has to be taken exactly as prescribed without missing a dose. For those struggling with the effects of analcohol use disorder, compliance with taking a daily dose can be problematic.

It’s easy to forget to take a dose or to intentionally skip it because of physical issues or struggles with recovery.

It was also the pill form of naltrexone that was initially approved for the treatment of opioid use disorder. For this indication, the pill is not ideal because of poor treatment adherence. Because of this, there is poor evidence supporting its benefits in reducing opioid use.

Monthly Naltrexone Injection

The Food and Drug Administration approved the once-a-month naltrexone shot treatment—marketed as Vivitrol—for use as a treatment for alcohol dependence in 2006. This form of naltrexone could be injected once and beslowly released into the system for a month. In 2010, the FDA also approved the use of Vivitrol to treat people with opioid dependence.

Research has found that a once-a-month naltrexone shot is effective in reducing alcohol use.For opioid use disorder, the extended-release injectable form of naltrexone is preferred because it requires only one injection each month. Research suggests that this leads to greater medication compliance.

Before initiating treatment with injectable naltrexone, your healthcare provider will perform a physical exam, may determine your liver function, and conduct a drug test. Because naltrexone is an opioid antagonist, taking it may lead toopioid withdrawalif you have taken an opioid medication within the last 10 days.

It is important to be opioid-free for a certain period of time before you begin receiving naltrexone injections.

Precautions and Contraindications

You should not receive monthly naltrexone injections or take other naltrexone-containing medications if you are actively using opioids. The Substance Abuse and Mental Health Services Administration (SAMHSA) says that people who are being treated with naltrexone may have a reduced tolerance to opioids after the dose goes away.

A reduced tolerance to opioids can lead to potentially life-threatening consequences when people take opioids at the same levels they previously used. Accidental overdose can occur, which may result in death.

If you believe that you have an alcohol or opioid use disorder or want to cut back on your use, talk to your doctor about your treatment options. Your doctor will perform an evaluation of your health and needs to determine if a monthly naltrexone injection is right for you.

If your doctor determines that this approach might be appropriate, your doctor will give you an intramuscular injection in the gluteal muscles every four weeks. You may find that medication adherence is easier than taking a daily pill because it only requires one injection each month.

The side effects of monthly naltrexone injections are similar to those of daily oral naltrexone. Possible side effects may include:

In one large study looking at the use of naltrexone to treat alcohol use disorder, of those taking a 380 milligram dose, 14.1% dropped out of the treatment due to side effects, including nausea, headache, and fatigue. Only 6.7% of the group receiving 190 milligrams discontinued treatment due to adverse side effects.

The study was one of the largest trials of subjects treated with medication for alcohol dependence. The researchers concluded that extended-release naltrexone was well tolerated and significantly reduced heavy drinking in actively drinking individuals.

Severe Side Effects

Severe side effects can also occur in some cases. These may include:

If you are having suicidal thoughts, contact theNational Suicide Prevention Lifelineat988for support and assistance from a trained counselor. If you or a loved one are in immediate danger, call 911.

If you are taking naltrexone to treat alcohol use disorder or opioid use disorder, you should seek medical attention immediately if you begin to experience signs of a serious allergic reaction, including trouble breathing, difficulty swallowing, or swelling of your mouth, face, or hands.

Research suggests that naltrexone can be effective in the treatment of both alcohol use disorder and opioid use disorder.

Naltrexone to Treat Alcohol Use Disorder

One study indicated that the injection of a 380 mg dose of naltrexone resulted in a 25% reduction of heavy drinking days, while a 190 mg dose reduced heavy drinking days 17%.

Research suggests that men may respond to naltrexone treatment more than women and that those who begin treatment after a period of drug or alcohol abstinence may experience greater treatment effects.

Studies also indicate that people who are given Vivitrol injection get variable blood levels and those who get higher blood levels experience fewer cravings.

Naltrexone to Treat Opioid Use Disorder

One study looking at the effectiveness of monthly naltrexone for the treatment of opioid use disorder found that the medication significantly improved abstinence from opioids. Participants treated with a monthly naltrexone injection were abstinent in 90% of the weeks during the study, on average, compared to only 35% abstinence in the placebo group.

In addition to improved abstinence, those in the naltrexone group also reported decreased drug cravings and fewer drug relapses.

A 2022 systematic review and meta-analysis found that injectable naltrexone was linked to better treatment retention and outcomes than oral naltrexone.

Takeaway

If you or a loved one have an alcohol or opioid use disorder, naltrexone is one treatment option that may help. Receiving this medication as a once-a-month shot can be an effective way to reduce your alcohol or drug use. The injectable form of the medication can improve treatment adherence, which can improve your outcomes and chances for recovery. If you think naltrexone might be a good choice for you, talk to your doctor about your treatment options.

If you or a loved one are struggling with substance use or addiction, contact theSubstance Abuse and Mental Health Services Administration (SAMHSA) National Helplineat1-800-662-4357for information on support and treatment facilities in your area.For more mental health resources, see ourNational Helpline Database.

If you or a loved one are struggling with substance use or addiction, contact theSubstance Abuse and Mental Health Services Administration (SAMHSA) National Helplineat1-800-662-4357for information on support and treatment facilities in your area.

For more mental health resources, see ourNational Helpline Database.

13 SourcesVerywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Substance Abuse and Mental Health Services Administration.Naltrexone.Trofimovitch D, Baumrucker SJ.Pharmacology update: Low-dose naltrexone as a possible nonopioid modality for some chronic, nonmalignant pain syndromes.Am J Hosp Palliat Care. 2019;36(10):907-912. doi:10.1177/1049909119838974Bolton MJ, Chapman BP, Van Marwijk H.Low-dose naltrexone as a treatment for chronic fatigue syndrome.BMJ Case Rep. 2020;13(1):e232502. doi:10.1136/bcr-2019-232502National Institute on Drug Abuse.How effective are medications to treat opioid use disorder?Substance Abuse and Mental Health Services Administration.An introduction to extended-release injectable naltrexone for the treatment of people with opioid dependence.SAMHSA Advisory. 2012;11(1):1-8.Garbutt JC, Kranzler HR, O’Malley SS, et al; Vivitrex Study Group.Efficacy and tolerability of long-acting injectable naltrexone for alcohol dependence: A randomized controlled trial.JAMA. 2005;293(13):1617-25. doi: 10.1001/jama.293.13.1617Food and Drug Administration.Highlights of prescribing information: Vivitrol (naltrexone for extended-release injectable suspension).Center for Substance Abuse Treatment.Chapter 5—extended-release injectable naltrexone. In:Incorporating Alcohol Pharmacotherapies Into Medical Practice. Substance Abuse and Mental Health Services Administration; 2009:49.Food and Drug Administration.Vivitrol medication guide.Jarvis BP, Holtyn AF, Subramaniam S, et al.Extended-release injectable naltrexone for opioid use disorder: a systematic review.Addiction. 2018;113(7):1188-1209. doi:10.1111/add.14180Brünen S, Bekier NK, Hiemke C, Korf F, Wiedemann K, Jahn H, Kiefer F.Therapeutic drug monitoring of naltrexone and 6β-naltrexol during anti-craving treatment in alcohol dependence: reference ranges.Alcohol Alcohol. 2019;54(1):51-55. doi: 10.1093/alcalc/agy067Krupitsky E, Nunes EV, Ling W, Illeperuma A, Gastfriend DR, Silverman BL.Injectable extended-release naltrexone for opioid dependence: a double-blind, placebo-controlled, multicentre randomised trial.Lancet Lond Engl. 2011;377(9776):1506-1513. doi:10.1016/S0140-6736(11)60358-9Zangiabadian M, Golmohammadi S, Nejadghaderi SA, Zahmatkesh MM, Nasiri MJ, Sadeghian M.The effects of naltrexone on retention in treatment and being opioid-free in opioid-dependent people: A systematic review and meta-analysis.Front Psychiatry. 2022;13:1003257. doi:10.3389/fpsyt.2022.1003257

13 Sources

Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Substance Abuse and Mental Health Services Administration.Naltrexone.Trofimovitch D, Baumrucker SJ.Pharmacology update: Low-dose naltrexone as a possible nonopioid modality for some chronic, nonmalignant pain syndromes.Am J Hosp Palliat Care. 2019;36(10):907-912. doi:10.1177/1049909119838974Bolton MJ, Chapman BP, Van Marwijk H.Low-dose naltrexone as a treatment for chronic fatigue syndrome.BMJ Case Rep. 2020;13(1):e232502. doi:10.1136/bcr-2019-232502National Institute on Drug Abuse.How effective are medications to treat opioid use disorder?Substance Abuse and Mental Health Services Administration.An introduction to extended-release injectable naltrexone for the treatment of people with opioid dependence.SAMHSA Advisory. 2012;11(1):1-8.Garbutt JC, Kranzler HR, O’Malley SS, et al; Vivitrex Study Group.Efficacy and tolerability of long-acting injectable naltrexone for alcohol dependence: A randomized controlled trial.JAMA. 2005;293(13):1617-25. doi: 10.1001/jama.293.13.1617Food and Drug Administration.Highlights of prescribing information: Vivitrol (naltrexone for extended-release injectable suspension).Center for Substance Abuse Treatment.Chapter 5—extended-release injectable naltrexone. In:Incorporating Alcohol Pharmacotherapies Into Medical Practice. Substance Abuse and Mental Health Services Administration; 2009:49.Food and Drug Administration.Vivitrol medication guide.Jarvis BP, Holtyn AF, Subramaniam S, et al.Extended-release injectable naltrexone for opioid use disorder: a systematic review.Addiction. 2018;113(7):1188-1209. doi:10.1111/add.14180Brünen S, Bekier NK, Hiemke C, Korf F, Wiedemann K, Jahn H, Kiefer F.Therapeutic drug monitoring of naltrexone and 6β-naltrexol during anti-craving treatment in alcohol dependence: reference ranges.Alcohol Alcohol. 2019;54(1):51-55. doi: 10.1093/alcalc/agy067Krupitsky E, Nunes EV, Ling W, Illeperuma A, Gastfriend DR, Silverman BL.Injectable extended-release naltrexone for opioid dependence: a double-blind, placebo-controlled, multicentre randomised trial.Lancet Lond Engl. 2011;377(9776):1506-1513. doi:10.1016/S0140-6736(11)60358-9Zangiabadian M, Golmohammadi S, Nejadghaderi SA, Zahmatkesh MM, Nasiri MJ, Sadeghian M.The effects of naltrexone on retention in treatment and being opioid-free in opioid-dependent people: A systematic review and meta-analysis.Front Psychiatry. 2022;13:1003257. doi:10.3389/fpsyt.2022.1003257

Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

Substance Abuse and Mental Health Services Administration.Naltrexone.Trofimovitch D, Baumrucker SJ.Pharmacology update: Low-dose naltrexone as a possible nonopioid modality for some chronic, nonmalignant pain syndromes.Am J Hosp Palliat Care. 2019;36(10):907-912. doi:10.1177/1049909119838974Bolton MJ, Chapman BP, Van Marwijk H.Low-dose naltrexone as a treatment for chronic fatigue syndrome.BMJ Case Rep. 2020;13(1):e232502. doi:10.1136/bcr-2019-232502National Institute on Drug Abuse.How effective are medications to treat opioid use disorder?Substance Abuse and Mental Health Services Administration.An introduction to extended-release injectable naltrexone for the treatment of people with opioid dependence.SAMHSA Advisory. 2012;11(1):1-8.Garbutt JC, Kranzler HR, O’Malley SS, et al; Vivitrex Study Group.Efficacy and tolerability of long-acting injectable naltrexone for alcohol dependence: A randomized controlled trial.JAMA. 2005;293(13):1617-25. doi: 10.1001/jama.293.13.1617Food and Drug Administration.Highlights of prescribing information: Vivitrol (naltrexone for extended-release injectable suspension).Center for Substance Abuse Treatment.Chapter 5—extended-release injectable naltrexone. In:Incorporating Alcohol Pharmacotherapies Into Medical Practice. Substance Abuse and Mental Health Services Administration; 2009:49.Food and Drug Administration.Vivitrol medication guide.Jarvis BP, Holtyn AF, Subramaniam S, et al.Extended-release injectable naltrexone for opioid use disorder: a systematic review.Addiction. 2018;113(7):1188-1209. doi:10.1111/add.14180Brünen S, Bekier NK, Hiemke C, Korf F, Wiedemann K, Jahn H, Kiefer F.Therapeutic drug monitoring of naltrexone and 6β-naltrexol during anti-craving treatment in alcohol dependence: reference ranges.Alcohol Alcohol. 2019;54(1):51-55. doi: 10.1093/alcalc/agy067Krupitsky E, Nunes EV, Ling W, Illeperuma A, Gastfriend DR, Silverman BL.Injectable extended-release naltrexone for opioid dependence: a double-blind, placebo-controlled, multicentre randomised trial.Lancet Lond Engl. 2011;377(9776):1506-1513. doi:10.1016/S0140-6736(11)60358-9Zangiabadian M, Golmohammadi S, Nejadghaderi SA, Zahmatkesh MM, Nasiri MJ, Sadeghian M.The effects of naltrexone on retention in treatment and being opioid-free in opioid-dependent people: A systematic review and meta-analysis.Front Psychiatry. 2022;13:1003257. doi:10.3389/fpsyt.2022.1003257

Substance Abuse and Mental Health Services Administration.Naltrexone.

Trofimovitch D, Baumrucker SJ.Pharmacology update: Low-dose naltrexone as a possible nonopioid modality for some chronic, nonmalignant pain syndromes.Am J Hosp Palliat Care. 2019;36(10):907-912. doi:10.1177/1049909119838974

Bolton MJ, Chapman BP, Van Marwijk H.Low-dose naltrexone as a treatment for chronic fatigue syndrome.BMJ Case Rep. 2020;13(1):e232502. doi:10.1136/bcr-2019-232502

National Institute on Drug Abuse.How effective are medications to treat opioid use disorder?

Substance Abuse and Mental Health Services Administration.An introduction to extended-release injectable naltrexone for the treatment of people with opioid dependence.SAMHSA Advisory. 2012;11(1):1-8.

Garbutt JC, Kranzler HR, O’Malley SS, et al; Vivitrex Study Group.Efficacy and tolerability of long-acting injectable naltrexone for alcohol dependence: A randomized controlled trial.JAMA. 2005;293(13):1617-25. doi: 10.1001/jama.293.13.1617

Food and Drug Administration.Highlights of prescribing information: Vivitrol (naltrexone for extended-release injectable suspension).

Center for Substance Abuse Treatment.Chapter 5—extended-release injectable naltrexone. In:Incorporating Alcohol Pharmacotherapies Into Medical Practice. Substance Abuse and Mental Health Services Administration; 2009:49.

Food and Drug Administration.Vivitrol medication guide.

Jarvis BP, Holtyn AF, Subramaniam S, et al.Extended-release injectable naltrexone for opioid use disorder: a systematic review.Addiction. 2018;113(7):1188-1209. doi:10.1111/add.14180

Brünen S, Bekier NK, Hiemke C, Korf F, Wiedemann K, Jahn H, Kiefer F.Therapeutic drug monitoring of naltrexone and 6β-naltrexol during anti-craving treatment in alcohol dependence: reference ranges.Alcohol Alcohol. 2019;54(1):51-55. doi: 10.1093/alcalc/agy067

Zangiabadian M, Golmohammadi S, Nejadghaderi SA, Zahmatkesh MM, Nasiri MJ, Sadeghian M.The effects of naltrexone on retention in treatment and being opioid-free in opioid-dependent people: A systematic review and meta-analysis.Front Psychiatry. 2022;13:1003257. doi:10.3389/fpsyt.2022.1003257

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