What is the use of Naltrexone (Opioid Receptor Antagonist)?

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Last updated: May 20, 2025View editorial policy

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From the Guidelines

Naltrexone is a recommended treatment for opioid use disorder, particularly for patients who are motivated and opioid-free, as it can help maintain abstinence and reduce cravings. The medication is available in various forms, including a 50-mg tablet taken daily or a monthly extended-release injection (Vivitrol) at 380mg 1. According to the most recent and highest quality study, naltrexone has been shown to be effective in maintaining abstinence from opioids in motivated populations, such as healthcare professionals 1.

Key Considerations

  • Patients must be opioid-free for 7-10 days before starting naltrexone to avoid precipitating withdrawal 1
  • Naltrexone works by blocking opioid receptors in the brain, reducing the pleasurable effects and cravings associated with alcohol and opioids 1
  • Common side effects include nausea, headache, dizziness, and liver enzyme elevations 1
  • Liver function should be monitored during treatment, with tests recommended at baseline and every three to six months 1

Treatment Guidelines

  • Naltrexone is contraindicated in patients with acute hepatitis, liver failure, or those currently taking opioid medications 1
  • It's most effective when combined with counseling or behavioral therapy as part of a comprehensive treatment program 1
  • Treatment duration varies based on individual needs but often continues for at least 3-6 months for alcohol dependence and potentially longer for opioid use disorder 1

Additional Recommendations

  • Clinicians should discuss their concerns with patients and provide an opportunity for them to disclose related concerns or problems 1
  • Patients with opioid use disorder should be offered or arranged to receive evidence-based treatment, usually medication-assisted treatment with buprenorphine or methadone maintenance therapy in combination with behavioral therapies 1
  • Naltrexone can be used in non-pregnant adults, and clinicians do not need a waiver to offer it for opioid use disorder as part of their practice 1

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Naltrexone Overview

  • Naltrexone is a broad opioid-receptor antagonist used in the management of alcohol dependence 2
  • It was the first medication approved by the United States Food and Drug Administration for the treatment of alcohol dependence since disulfiram 2

Efficacy of Naltrexone

  • Oral naltrexone has been shown to significantly reduce the risk of relapsing to heavy drinking compared to placebo 2
  • Meta-analyses of trials have revealed that oral naltrexone is effective in reducing relapse to heavy drinking but less effective in enhancing abstinence 2
  • The effect size of naltrexone is modest, in the .15 to .2 range 2
  • Injectable, sustained-release naltrexone has also shown efficacy in the treatment of opioid dependence 3

Tolerability and Safety

  • The tolerability of naltrexone is reasonable, with the most common side-effect being nausea 2
  • Hepatotoxicity with naltrexone has not emerged as a clinical problem at the standard 50 mg dose, though at higher doses hepatotoxicity is of concern 2
  • Adverse events associated with naltrexone are minimal and generally mild 3

Use in Comorbid Psychiatric Disorders

  • Naltrexone and disulfiram have been found to be safe pharmacotherapeutic agents for dually diagnosed individuals with depression for the treatment of alcohol use disorders 4
  • There is no relationship between the diagnosis of depression and medication treatment on alcohol use outcomes, psychiatric symptoms, or the reporting of side effects for these medications 4

Combination Therapy

  • The combination of naltrexone with cognitive behavioural relapse prevention therapy is beneficial in alcohol dependent patients 5
  • There is no advantage of the combination of naltrexone and disulfiram for the treatment of alcohol dependence in dually diagnosed individuals 6

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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