Naltrexone is approved for the treatment of alcohol use dependence in addition to opioid dependence. Its efficacy in reducing alcohol craving and relapse is primarily due to which mechanism?

• A Blockade of NMDA receptors reducing alcohol-induced glutamatergic excitation
• B Inhibition of dopamine reuptake in the nucleus accumbens reducing reward-seeking behavior
• C Enhancement of GABAergic transmission reducing alcohol withdrawal anxiety
• D Antagonism at mu-opioid receptors blocking endorphin-mediated reinforcement of alcohol consumption ✓

Explanation

Naltrexone reduces alcohol craving and relapse by blocking mu-opioid receptors, which disrupts the endorphin-mediated reinforcement pathway triggered by alcohol consumption. This reduces the pleasurable effects of drinking. Option A describes an NMDA mechanism not relevant to naltrexone. Option C describes a GABAergic mechanism seen with benzodiazepines. Option B describes a stimulant-like mechanism, not an opioid antagonist.

Reference: Katzung Basic and Clinical Pharmacology, 15th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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