Which pharmacological property distinguishes aripiprazole from most other second-generation antipsychotics?

• A Partial agonism at dopamine D2 and serotonin 5-HT1A receptors ✓
• B Irreversible antagonism of dopamine D2 receptors
• C Selective antagonism of serotonin 5-HT2A without any dopaminergic action
• D Full agonism at dopamine D1 receptors

Explanation

Aripiprazole is a dopamine system stabiliser: it is a partial agonist at D2 and 5-HT1B receptors and an antagonist at 5-HT2B. In hyperdopaminergic mesolimbic states it acts functionally as an antagonist, while in hypodopaminergic nigrostriatal regions its intrinsic activity preserves tone, explaining its low propensity for extrapyramidal symptoms and hyperprolactinaemia. Option C describes pure 5-HT2B blockade, which is closer to older agents like ritanserin, not aripiprazole.

Reference: Katzung's Basic and Clinical Pharmacology, 16th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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