Naltrexone is a medication used in the treatment of substance use disorders. It assists individuals by managing cravings and diminishing the rewarding effects associated with substance use, supporting their recovery journey.
Understanding Naltrexone’s Action
Naltrexone functions as an opioid receptor antagonist in the brain. It primarily binds to and blocks mu-opioid receptors, preventing external opioids or the body’s natural endorphins from binding.
This blocking action reduces cravings and mitigates the euphoric effects of opioids and alcohol. Individuals taking naltrexone will not experience the usual “high” if they use opioids, nor the reinforcing “buzz” from alcohol. Naltrexone itself does not produce opioid-like effects, is not addictive, and does not cause withdrawal symptoms when its use is discontinued.
Naltrexone for Alcohol Use Disorder
For Alcohol Use Disorder (AUD), naltrexone reduces heavy drinking days, lessens cravings, and supports abstinence. It works by decreasing the rewarding sensations of alcohol consumption, helping individuals reduce intake. Naltrexone can lead to reduced relapse rates and lower alcohol consumption, especially when combined with other supportive measures.
Naltrexone for AUD is available as an oral tablet (e.g., ReVia or Depade) and an extended-release injectable form (Vivitrol). The oral tablet is typically taken daily, while the injectable form is administered monthly. Both oral and injectable formulations have shown similar efficacy in reducing heavy drinking days and improving outcomes for individuals with AUD.
Naltrexone for Opioid Use Disorder
Naltrexone is an effective treatment for Opioid Use Disorder (OUD), primarily by blocking opioid effects and reducing relapse risk. It prevents opioids from producing euphoric and sedative effects, removing the reinforcing aspect of opioid use. A critical requirement before initiating naltrexone for OUD is that individuals must be completely opioid-free, typically for at least 7 to 14 days, to prevent severe precipitated withdrawal symptoms.
This opioid-free interval is essential because naltrexone can rapidly displace opioids from their receptors, leading to acute withdrawal if opioids are still present in the system. Naltrexone is available as an oral tablet and an extended-release injectable form for OUD treatment. The monthly injectable form, Vivitrol, may offer advantages in adherence and effectiveness compared to the daily oral tablet. While naltrexone significantly reduces the risk of relapse, it is important to understand that if an individual relapses after a period of abstinence, their opioid tolerance may have decreased, increasing the risk of overdose.
Important Considerations for Use
Potential side effects of naltrexone are generally mild and often improve over time. Common side effects include nausea, headache, dizziness, vomiting, painful joints, and muscle cramps. For the injectable form, reactions at the injection site, such as pain or swelling, can also occur.
Naltrexone is not suitable for everyone and has specific contraindications. It should not be used by individuals with acute hepatitis or liver failure, or those currently using or physically dependent on opioids. Healthcare providers typically recommend liver function tests before and during naltrexone treatment to monitor liver health.
Integrating Naltrexone into Treatment
Naltrexone is most effective as part of a comprehensive treatment plan, not as a standalone solution. Its benefits are maximized when combined with other therapeutic approaches. Behavioral therapies, counseling, and support groups (e.g., 12-step programs) are important components of this integrated approach.
This combination addresses the psychological and social aspects of addiction, providing a holistic pathway to recovery. Medication-assisted treatment (MAT), including naltrexone, enhances sustained recovery and improved long-term outcomes.