Mirtazapine's mechanism of antidepressant action is best described as:
- A Selective serotonin reuptake inhibition with secondary noradrenaline release
- B Inhibition of both serotonin and noradrenaline reuptake transporters (SNRI)
- C Blockade of presynaptic alpha-2 autoreceptors and heteroreceptors, increasing NE and 5-HT release, combined with 5-HT2 and 5-HT3 receptor antagonism ✓
- D Monoamine oxidase A inhibition, increasing synaptic monoamine levels
Correct answer: C. Blockade of presynaptic alpha-2 autoreceptors and heteroreceptors, increasing NE and 5-HT release, combined with 5-HT2 and 5-HT3 receptor antagonism
Explanation
Mirtazapine is a noradrenergic and specific serotonergic antidepressant (NaSSA). It blocks presynaptic alpha-2 autoreceptors (increasing NE release) and alpha-2 heteroreceptors on serotonergic neurons (increasing 5-HT release). It also antagonises postsynaptic 5-HT2A, 5-HT2C, and 5-HT3 receptors, channelling serotonergic activity specifically through 5-HT1A receptors. H1 antagonism accounts for its sedation.
Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.