A 55-year-old man with hypertensive emergency is started on intravenous sodium nitroprusside. The drug's rapid vasodilatory effect is mediated by which mechanism?
- A Release of nitric oxide ✓
- B Beta-adrenergic receptor blockade
- C Angiotensin-converting enzyme inhibition
- D Calcium channel blockade
Correct answer: A. Release of nitric oxide
Explanation
Sodium nitroprusside is metabolized to nitric oxide, which activates guanylyl cyclase, increases cyclic GMP, and relaxes vascular smooth muscle. It has no effect on ACE, beta receptors, or calcium channels. This direct nitric oxide donation makes it a potent, short-acting vasodilator suitable for hypertensive emergencies.
Reference: Katzung Basic & Clinical Pharmacology, 14th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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