Naltrexone is a medication used in the treatment of substance use disorders. It helps individuals manage their recovery by supporting abstinence.
Understanding Naltrexone
Naltrexone is an opioid antagonist that blocks the effects of opioids in the body. It is not an opioid and does not carry the risk of physical dependence or addiction. Available in oral tablet and extended-release injectable forms, the oral tablet is typically taken daily, while the injectable (Vivitrol) is administered monthly.
Unlike medications that activate opioid receptors, naltrexone does not produce euphoric effects or cause sedation. This makes it suitable for long-term recovery without contributing to substance dependence.
How Naltrexone Works
Naltrexone functions by binding to opioid receptors in the brain. By occupying these receptors, it prevents external opioids (such as heroin, morphine, or oxycodone) from attaching and producing their typical euphoric and sedative effects.
The medication also impacts the brain’s reward system for alcohol. When alcohol is consumed, the body releases natural opioids (endorphins) that contribute to pleasurable feelings. Naltrexone blocks these endorphins from binding, reducing alcohol’s rewarding effects and diminishing cravings. This mechanism helps decrease the desire for both opioids and alcohol by altering the brain’s response.
Naltrexone’s Role in Managing Substance Use
Naltrexone does not alleviate acute withdrawal symptoms. As an opioid receptor antagonist, it blocks opioid effects rather than mimicking them. If an individual is physically dependent on opioids and takes naltrexone, it can trigger immediate and severe withdrawal symptoms because it rapidly displaces opioids from the receptors.
Its primary function is to prevent relapse by blocking the euphoric effects of opioids and reducing cravings for alcohol and opioids. It helps individuals maintain abstinence by making substance use less rewarding, diminishing the motivation to use these substances over time. This makes it a tool for long-term recovery, not a solution for acute withdrawal discomfort.
Naltrexone modulates the brain’s response to substances, supporting sustained reduction in use. It does not address the physical discomfort of detox, such as nausea, muscle aches, or anxiety. Instead, its role is to support individuals after they have completed detoxification and are no longer experiencing active withdrawal.
When Naltrexone is Used in Treatment
Naltrexone is typically prescribed after detoxification is complete and acute withdrawal symptoms have subsided. For opioid dependence, individuals should abstain from opioids for 7 to 10 days before starting naltrexone to avoid precipitated withdrawal. For alcohol use disorder, waiting until detox is complete also prevents strong side effects.
The medication is part of a comprehensive treatment plan, often including counseling and behavioral therapies. Medical supervision is important to monitor progress and manage potential side effects.
Naltrexone is approved by the U.S. Food and Drug Administration (FDA) for treating both opioid and alcohol use disorders.