A pharmaceutical company develops a selective alpha-2A adrenoceptor agonist for treating ADHD. The drug reduces norepinephrine release from presynaptic terminals in the prefrontal cortex. Which drug among the following shares this predominant mechanism and is currently approved for ADHD?
- A Atomoxetine
- B Guanfacine ✓
- C Modafinil
- D Bupropion
Correct answer: B. Guanfacine
Explanation
Guanfacine is a selective alpha-2A adrenoceptor agonist approved for ADHD (non-stimulant). It acts on postsynaptic alpha-2A receptors in the prefrontal cortex to strengthen signal-to-noise ratio and improve working memory, while presynaptic alpha-2 activation reduces excessive norepinephrine release. Atomoxetine is a selective norepinephrine reuptake inhibitor; modafinil promotes wakefulness via histamine/orexin pathways; bupropion inhibits dopamine and norepinephrine reuptake.
Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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