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Naltrexone Side Effects, Use in Addiction Treatment, and Rehab Programs

For those struggling with alcohol or opioid addiction, what’s commonly referred to as MAT—short for medication-assisted treatment or medication for addiction treatment—can help people quit drinking and using drugs to maintain long-term sobriety.1 This evidence-based treatment approach combines behavioral therapy and medication to help people with both alcohol and opioid use disorders. One of the most common MAT medications that can be used for both is called naltrexone.

If you or someone you care about is struggling with opioid or alcohol addiction and you want to know what naltrexone is used for, you may benefit from learning more about naltrexone, precautions to be aware of before you start using it, potential naltrexone side effects, interactions with other medications, and how to seek rehab to get started on the path to recovery.

What Is Naltrexone Used For?

Naltrexone is an FDA-approved medication that is used as a part of MAT to treat opioid use disorder (OUD) and alcohol use disorder (AUD).1 Naltrexone is available in two formulations—it can be taken daily as an oral tablet or administered as a once-per-month extended-release intramuscular injectable (available under the brand name Vivitrol).2,3 The daily pill form is most often used for AUD, while the long-acting injectable is FDA-approved for treating both OUD and AUD.1

When treating either alcohol or opioid addiction, naltrexone therapy may be first initiated after completion of the detox and withdrawal management period.1,2 For OUD treatment, people should be abstinent from short-acting opioids for at least 7 days, and for 10–14 days for long-acting opioids. For AUD, people must no longer be physically dependent on alcohol or other substances and have undergone alcohol detox.1

Naltrexone is an opioid receptor antagonist.1,2 Unlike buprenorphine or methadone, which are opioid receptor agonist medications used to manage opioid withdrawal and treat OUD, naltrexone binds to and prevents the activation of these same opioid receptors—effectively blocking the pleasurable or euphoric effects associated with opioid use, while also reducing opioid cravings.2,3

When used in the treatment of AUD, this same opioid receptor blockade is thought to diminish the reward associated with continued drinking. Should you relapse and use opioids or drink alcohol while taking naltrexone, some of the reinforcing or euphoric effects of these substances will be diminished. This mechanism is thought to reduce a person’s incentive to continue using these substances, which can ultimately help them stay sober.1,2

Is Naltrexone Addictive?

People who struggle with alcohol and opioid addiction may have concerns about using naltrexone for addiction treatment and wonder if they are just substituting one substance for another. To clarify, naltrexone is not an opioid, nor is it addictive or habit-forming. Naltrexone dependence will not develop with continued use, so there is no risk of withdrawal symptoms when you stop using it.1 Naltrexone use can reduce your drinking and drug use by decreasing your desire to use alcohol or opioids—helping you to remain abstinent and keeping you on track with your recovery, even if you relapse.4

It’s important to keep in mind that while it blocks opioid activity, naltrexone does not block many of the intoxicating effects of alcohol, such as those that affect judgment and coordination.4 However, since it inhibits opioid receptor activation, naltrexone blocks the effects of opioid drugs and diminishes the reinforcing effects associated with both opioid use and drinking alcohol. As part of a comprehensive addiction treatment plan, naltrexone can help you remain in recovery by allowing you to slow or stop the use of these substances.1,2

Naltrexone Side Effects

People may experience side effects when taking naltrexone. However, one study of individuals who used naltrexone for alcohol addiction showed that only a small minority of participants experienced these effects.4 According to the Substance Abuse and Mental Health Services Administration (SAMHSA), common naltrexone side effects can include:1

  • Headaches.
  • Sleepiness.
  • Dizziness.
  • Nausea and vomiting.
  • Decreased appetite.
  • Body aches.

In addition, SAMHSA reports that people may experience rare, yet more severe side effects, such as:1

  • Localized pain and inflammation at the injection site.
  • Liver inflammation.
  • Drug allergy (e.g. skin rash, swelling of the tongue, wheezing or other breathing difficulty).
  • Depressed mood.

Precautions to Take Before Starting Naltrexone

It’s important to take certain precautions before starting naltrexone. All concerns should be reviewed with your physician and/or pharmacist. Education and consultation about opioid overdose should also be offered by your prescribing physician.5

There is a potential risk of overdose, coma, or death if you relapse and use opioids after detoxification due to reduced opioid tolerance. After using naltrexone, should the drug’s opioid receptor blockade be allowed to fade, patients may similarly be at increased risk of opioid overdose at relatively lower doses than those previously used. While naltrexone is being used, attempts to overcome its receptor blocking effects and get high by using large amounts of opioids also pose the risk of opioid toxicity or fatal overdose.5

Those who have impaired kidney function are advised to use naltrexone with caution, as it is primarily excreted in urine.5 People should also be aware that naltrexone could potentially complicate or worsen pre-existing liver conditions or result in liver injury in some people. Simultaneously using it with other potentially hepatotoxic (drug-induced liver damage) medications, such as high doses of acetaminophen (Tylenol), may increase the risk of liver injury.2,5,6 Women who are trying to become or are pregnant should discuss naltrexone use with their physicians, as it has not been well studied in pregnant women. The injectable form of naltrexone is not advised for use by pregnant women.2

People should inform medical personnel, such as emergency room staff, doctors, and others, that they are taking naltrexone. You may receive a naltrexone medication card from your physician to use for this purpose. It can help to ensure that you receive proper treatment in case of emergencies and appropriate pain management if necessary.4,5

Those with histories of depression or suicidal ideation should be aware that naltrexone could worsen their symptoms. Should this be the case for you, and if you notice increased thoughts of self-harm, it’s important to contact your doctor or 911 right away.6

Naltrexone Interactions With Other Drugs

Naltrexone could potentially interact with different substances, including prescription and over-the-counter medications. People who are using opioid painkillers, are dependent on opioids, or are in acute withdrawal from opioids should not use naltrexone.5

Certain cough medications can contain opioid pain medications, so you should discuss the use of these medications with your doctor or pharmacist.6 In addition, people who use other medications that alter liver function should discuss the proper naltrexone dosage with their doctors, as these medications could impact levels of naltrexone in the body.4

Different potential effects could occur as a result of certain drug interactions. For example, if you use opioids while taking naltrexone, you can experience withdrawal symptoms, such as sweating, shaking, nausea, and vomiting.6 As previously mentioned, using naltrexone can lower your tolerance threshold for opioids, and after you stop using it you will have a lower tolerance. You should not resume using the same dose of opioids after an abstinent period due to the heightened risk of overdose.6

Alcohol and Opioid Addiction Treatment Programs

Naltrexone, as well as other medications, can be beneficial in helping you stay sober as you start the path to recovery. However, many people require more than just medications to recover from AUD or OUD.7 If you or someone you care about wants to stop substance abuse, you should know that medications, paired with counseling and behavioral therapies, provide a comprehensive, whole-person approach to treatment and recovery.1 Treatment can also provide you with support, motivation, and direction so that you can avoid relapse and cope with life’s problems without substances.7

You may enter inpatient or outpatient treatment, depending on your specific needs. You may benefit from different levels of care as you progress through treatment and step up or down in intensity as needed.2 Regardless of the setting, you should receive comprehensive, individualized care that includes a combination of medication and different evidence-backed therapies, such as:2

  • Cognitive behavioral therapy (CBT), which focuses on helping you identify and change unhelpful thoughts and behaviors that contribute to substance use and teaches you healthier stress management and coping skills so that you can stay sober and avoid relapse.
  • Motivational interviewing, which helps you identify your personal reasons for wanting to stop using substances and aims to increase your motivation to make positive changes in your life.
  • Family therapy, which can help identify family issues and concerns, as well as address family members’ potential biases around using medications like naltrexone for drug addiction treatment.

Find Drug and Alcohol Rehab Programs

When you’re ready to take back control of your life, you may wish to begin searching for treatment centers. Rehab programs are located throughout the U.S., and many offer specialized treatment that can cater to individual needs. You can use SAMHSA’s Find Treatment tool to search for facilities. Many state government websites will provide local drug and alcohol resources to those in need. To find your state government’s website, do a web search for your state name and ‘.gov.’ Once your state website is located, substance use resources shouldn’t be hard to find, and they should provide further phone contacts for your assistance.

American Addiction Centers (AAC) is a leading provider of addiction treatment programs and has trusted rehab facilities across the country. You can find an opioid/alcohol rehab center in your area using our directory. You can also instantly verify your health insurance coverage to check your substance abuse and mental health benefits.

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