Which medication blocks opioid receptors to reduce the pleasant effects of alcohol?

• A. Naltrexone
• B. Acamprosate
• C. Disulfiram
• D. Benzodiazepine

Answer: (A)

Blocking opioid receptors to blunt alcohol’s rewarding effects is achieved with an opioid receptor antagonist. Naltrexone binds to mu-opioid receptors, preventing endogenous opioids released during drinking from activating reward pathways. This diminishes the euphoria and craving associated with alcohol, helping to prevent relapse in alcohol use disorder. It’s used as part of a treatment plan that includes psychosocial support, and is not given for acute intoxication. Be aware that naltrexone can affect liver function and is contraindicated in people currently dependent on opioids without proper management, since it may precipitate withdrawal. The other medications work through different mechanisms: acamprosate helps stabilize glutamatergic signaling to support abstinence, disulfiram causes an unpleasant reaction with alcohol by blocking acetaldehyde dehydrogenase, and benzodiazepines are used mainly for withdrawal symptoms, not to block the rewarding effects of alcohol.