Naltrexone is a medication healthcare providers use to help individuals manage certain substance use disorders. It is approved by the Food and Drug Administration (FDA) for treating opioid dependence and alcohol use disorder. Naltrexone is also being explored as an off-label treatment for methamphetamine use disorder. This medication offers a different approach to supporting recovery.
How Naltrexone Works
Naltrexone functions as an opioid receptor antagonist, primarily targeting the mu-opioid receptor. It binds to these receptors without activating them, blocking other opioid molecules, such as heroin or morphine, from attaching and producing euphoric effects. The medication’s influence extends beyond direct opioid blockade, impacting the brain’s reward system. Opioid receptors are part of the body’s natural opioid system, which interacts with various neurotransmitters, including dopamine. By blocking these receptors, naltrexone can help rebalance reward pathways that become dysregulated with chronic substance use, potentially reducing cravings.
While methamphetamine is not an opioid, its use also affects the brain’s dopamine system, leading to feelings of pleasure and reinforcement. Research suggests that the brain’s natural opioid system can modulate dopamine release, particularly in chronic drug use. Naltrexone is hypothesized to affect methamphetamine cravings by indirectly influencing these dopamine pathways, potentially blunting the reward response associated with methamphetamine use.
Naltrexone’s Application in Methamphetamine Use Disorder
Naltrexone is currently used off-label for methamphetamine use disorder (MUD). It is available as an oral tablet, typically taken daily, and as an extended-release intramuscular injectable formulation administered once a month. The injectable form can offer a sustained release, which may improve adherence.
Current research on naltrexone’s effectiveness in reducing methamphetamine cravings, use, or relapse rates shows promising trends, though studies are ongoing. Some clinical trials have indicated that naltrexone can attenuate the subjective effects of amphetamine and reduce cravings. For instance, in chronic models of amphetamine exposure, naltrexone has been shown to significantly reduce dopamine release, suggesting an engagement of the opioid system in the later stages of drug use.
Naltrexone is not considered a standalone cure for MUD. Instead, it is typically integrated into a comprehensive treatment strategy. This approach often includes behavioral therapies and psychosocial support to address the multifaceted nature of addiction. The medication serves as a supportive tool to help individuals manage cravings and reduce relapse.
Important Considerations for Naltrexone Treatment
Individuals considering naltrexone for methamphetamine use disorder should be aware of potential side effects, which can include nausea, headache, and reactions at the injection site for the injectable form. These effects are generally manageable and should be discussed with a healthcare provider.
Specific contraindications must be carefully considered before starting naltrexone. The medication should not be used by individuals who are currently taking opioids or are experiencing opioid withdrawal symptoms, as it can precipitate severe withdrawal. A period of being opioid-free, typically 7 to 10 days for short-acting opioids, is recommended before initiating naltrexone treatment. Individuals with severe liver disease should also avoid naltrexone.
Combining the medication with behavioral therapies, such as cognitive-behavioral therapy (CBT) or contingency management, and ongoing psychosocial support is highly recommended. Medical supervision is necessary throughout treatment to monitor for side effects, adjust dosages, and ensure the treatment plan is effective and safe.