Naltrexone is a medication approved for Alcohol Use Disorder (AUD). It helps reduce heavy drinking and prevent relapse for individuals managing alcohol consumption. This medication is typically integrated into a broader treatment approach that includes counseling and support.
How Naltrexone Works in the Body
Naltrexone operates by interacting with specific mu-opioid receptors in the brain. Alcohol consumption triggers endorphin release, which binds to these receptors, contributing to feelings of pleasure and reward. Naltrexone acts as an opioid antagonist, occupying these receptors without activating them.
This blocks endorphins from attaching, diminishing alcohol’s pleasurable effects. Unlike some other AUD medications, naltrexone does not create an adverse physical reaction to alcohol. Instead, it aims to reduce the reinforcing effects of drinking, which can help lessen cravings and the desire to consume alcohol.
Duration of Naltrexone’s Effects
The duration naltrexone blocks alcohol effects depends on its formulation. Oral naltrexone, a daily pill, provides effects lasting approximately 24 hours. This daily effectiveness is supported by the drug’s half-life and its active metabolite, 6-beta-naltrexol, which has a longer half-life.
This extended presence of the metabolite contributes to the sustained blocking effect throughout a 24-hour period, supporting once-daily dosing. For individuals preferring a less frequent dosing schedule, an extended-release injectable form, Vivitrol, is available. This intramuscular injection is administered once a month, delivering a continuous release of naltrexone for approximately 30 days.
Factors Influencing Naltrexone’s Active Period
Several individual factors influence how long naltrexone remains effective. An individual’s metabolism, how quickly their body processes and eliminates medications, plays a significant role. Some people may metabolize the drug faster or slower, affecting its active period.
Liver function is another influencing factor, as naltrexone is metabolized in the liver. Impaired liver function can alter the drug’s breakdown and elimination rates. The prescribed dosage also directly impacts the drug’s concentration and the duration of its therapeutic effect.
Finally, the specific naltrexone formulation (daily oral pill or monthly injectable) dictates its general active period. Individual responses can vary due to these physiological differences.
What to Expect While Taking Naltrexone
When taking naltrexone, individuals may find alcohol’s usual pleasurable or rewarding sensations diminished. This can lead to a reduction in the desire to drink heavily or to continue drinking. The medication helps “unlearn” the positive reinforcement associated with alcohol use.
Naltrexone does not eliminate the physical ability to drink alcohol. If an individual drinks while on naltrexone, they might find the experience less satisfying. This reduced reward can potentially lead to consuming more alcohol than usual to achieve a desired effect, which can be harmful.
Naltrexone is not a standalone treatment for Alcohol Use Disorder. Its effectiveness is enhanced when used with other therapeutic interventions, such as counseling, behavioral therapy, or support groups. Combining medication with psychosocial support offers a comprehensive approach to managing AUD.