How does naltrexone work for alcohol
Pro Research Analysisby 
Searched over 200M research papers
Naltrexone's Mechanism of Action in Alcohol Use Disorder
Introduction to Naltrexone and Alcohol Use Disorder
Naltrexone is an opioid receptor antagonist widely used in the treatment of alcohol use disorder (AUD). Its efficacy in reducing alcohol consumption and preventing relapse has been supported by numerous studies. This article synthesizes the mechanisms by which naltrexone exerts its effects on alcohol use, focusing on its impact on subjective responses to alcohol, craving, and drinking behavior.
Attenuation of Hedonic Effects and Potentiation of Aversive Effects
Naltrexone works by altering the subjective experience of alcohol consumption. It reduces the pleasurable effects (hedonic effects) of alcohol and increases its aversive effects. Meta-analyses have shown that naltrexone significantly reduces alcohol craving and stimulation while increasing sedation and negative mood in individuals consuming alcohol. This dual action helps decrease the desire to drink and the enjoyment derived from drinking, thereby reducing overall alcohol intake.
Reduction in Alcohol Craving and Self-Administration
Several studies have demonstrated that naltrexone effectively reduces alcohol craving and self-administration. In controlled laboratory settings, naltrexone-treated individuals reported lower levels of craving and consumed fewer alcoholic drinks compared to those given a placebo . This reduction in craving is partly attributed to naltrexone's ability to activate the hypothalamo-pituitary-adrenocortical (HPA) axis, leading to increased cortisol levels, which are negatively correlated with alcohol craving.
Impact on Subjective Responses and Drinking Behavior
Naltrexone blunts the positive subjective effects of alcohol, such as feelings of euphoria and stimulation. This effect is particularly pronounced in certain subgroups, including women and individuals with the A118G polymorphism of the mu-opioid receptor gene (OPRM1). By reducing the rewarding effects of alcohol, naltrexone decreases the motivation to consume more alcohol, thereby aiding in the reduction of drinking behavior.
Moderation of Affect and Alcohol Use
Naltrexone also disrupts the association between affect (emotional state) and alcohol use. In adolescents, higher blood alcohol concentration (BAC) levels were associated with greater negative affect (NA) during drinking episodes when on naltrexone. This increased NA was linked to reduced subsequent alcohol consumption, suggesting that naltrexone may help break the cycle of using alcohol to manage negative emotions.
Synergistic Effects with Psychosocial Therapies
The combination of naltrexone with cognitive behavioral therapy (CBT) has shown enhanced efficacy in treating alcohol dependence. Naltrexone increases control over alcohol-related thoughts and urges, making individuals more resistant to relapse when combined with CBT. This synergistic effect highlights the importance of integrating pharmacotherapy with psychosocial interventions for optimal treatment outcomes.
Conclusion
Naltrexone is a valuable pharmacological tool in the treatment of alcohol use disorder. By reducing the pleasurable effects of alcohol, increasing its aversive effects, and lowering alcohol craving, naltrexone helps individuals reduce their alcohol consumption and maintain sobriety. Its efficacy is further enhanced when combined with psychosocial therapies, making it a comprehensive approach to managing AUD.
Sources and full results
Most relevant research papers on this topic