Naltrexone Side Effects: What To Expect

Medically Reviewed by Johnelle Smith, M.D. on March 17, 2022

Naltrexone (Vivitrol, ReVia) is a medication prescribed to treat alcohol use disorder and opioid use disorder. Side effects, including nausea and anxiety, can occur.

Side Effects Of Naltrexone

When taken as directed, naltrexone can help reduce cravings for alcohol and opiates, and block their effects on the brain. Side effects while taking this medication, however, can occur.

Naltrexone is prescribed in the form of a pill (ReVia, Depade) or a monthly shot (Vivitrol) injected into the muscle. How long side effects last may vary from person to person.

Read more about the benefits of taking Naltrexone during addiction recovery

Short-Term Side Effects Of Naltrexone

Naltrexone is an opioid antagonist that binds to and blocks opioid receptors in the brain. Taken as prescribed, its use may lead to certain side effects.

Side effects of naltrexone might include:

  • headache
  • nausea or vomiting
  • loss of appetite
  • diarrhea
  • constipation
  • restlessness
  • upset stomach
  • dizziness
  • difficulty falling or staying asleep (insomnia)
  • teary eyes
  • drowsiness
  • low or high energy
  • muscle or joint pain

Read more about how Naltrexone can cause nausea

Serious side effects, although rare, can also occur. If you experience serious side effects while taking naltrexone, tell your prescribing doctor right away.

Adverse side effects may include:

  • confusion
  • hallucinations
  • severe vomiting or diarrhea
  • blurred vision

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Long-Term Effects Of Naltrexone

Naltrexone is not habit-forming, nor does it have an abuse potential. There are no long-term side effects associated with the use of this medication when taken as directed.

Naltrexone Side Effects FAQs

It’s common to have questions about taking naltrexone for opioid use disorder or alcohol addiction. Find answers to frequently asked questions about potential side effects of naltrexone.

❓ Is Naltrexone Addictive?

✔️ Naltrexone is not physically or psychologically addictive. It doesn’t cause physical dependence, and as a result, does not result in withdrawal with reduced or stopped drug use.

This makes it different from other medications for opioid use disorder such as methadone and buprenorphine (Suboxone)—both of which can be habit-forming.

❓ Is Naltrexone An Opioid?

✔️ Naltrexone is not an opioid. It belongs to a class of drugs known as opioid antagonists, meaning it binds to and blocks opioid receptors in the body.

❓ Does Naltrexone Affect Mood?

✔️ The effects of naltrexone on mood can vary from person to person. While some people see improved mood while taking naltrexone, there have been reports of symptoms of depression.

Potential effects on mood while taking naltrexone include:

  • low mood
  • excitability
  • restlessness
  • nervousness

Changes in mood while taking naltrexone can also be influenced by other factors, including co-occurring mental health issues, stress, and post-acute withdrawal syndrome (PAWS).

❓ Does Naltrexone Affect Weight?

✔️ Naltrexone can cause decreased appetite. Because of this, weight loss has been reported in some people who take naltrexone. Weight gain is not a reported side effect.

Read more about how Naltrexone affects weight

❓ Does Naltrexone Cause Weird Dreams?

✔️ Some people who take naltrexone have reported experiencing very vivid dreams or nightmares while taking naltrexone for drug or alcohol addiction.

Read more about how Naltrexone can cause dreams

❓ Does Naltrexone Cause Hallucinations?

✔️ Hallucinations are not a common side effect of naltrexone. However, this can be a sign of an adverse reaction and should be reported to your prescribing doctor right away.

Hallucinations can be:

  • visual (i.e. seeing things)
  • auditory (i.e. hearing things)
  • tangible (i.e. feeling sensations)

Read more about hallucinations caused by Naltrexone

❓ Can Naltrexone Cause Erectile Dysfunction?

✔️ Naltrexone has been associated with early morning erections, reduced sexual desire, and other sexual side effects in some people.

Read more about the sexual side effects of Naltrexone

❓ Can Naltrexone Cause Mania?

✔️ Mania is not a common side effect of naltrexone. Naltrexone may improve or potentially exacerbate symptoms of mania in people with bipolar disorder who take this medication.

Read more about Naltrexone and manic episodes

❓ Is Naltrexone Bad For Your Liver?

✔️ Naltrexone is commonly prescribed for people who have impaired liver function as a result of alcoholism or drug abuse. Acute liver injury from naltrexone use is rare but can occur.

Symptoms of liver injury while taking naltrexone may include a yellowing of the skin or eyes (jaundice), chronic stomach pain, or excessive fatigue.

Read more about how Naltrexone can lead to liver damage

❓ Can Naltrexone Help With Anxiety?

✔️ The use of naltrexone during drug and alcohol treatment has been associated with improved mood. Feelings of nervousness or restlessness, however, can occur.

Call Today To Learn More About Naltrexone Treatment

Naltrexone is a prescription drug commonly used for helping formerly addicted individuals maintain recovery from alcohol or opioid addiction by reducing cravings.

For more information about naltrexone, its side effects, or how to find naltrexone treatment options, call our helpline to speak to one of our staff today.

This page does not provide medical advice. See more

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Medically Reviewed by
Johnelle Smith, M.D. on March 17, 2022
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