Sodium nitroprusside MCQs With Answer provides B.Pharm students a focused, exam-ready review of this potent vasodilator. This introduction and set of multiple-choice questions cover sodium nitroprusside pharmacology, mechanism of action (NO release and soluble guanylate cyclase activation), clinical indications (hypertensive emergencies, controlled hypotension), dosing and IV infusion practices, pharmacokinetics, metabolism to cyanide/thiocyanate, monitoring, adverse effects, antidotes (hydroxocobalamin, sodium thiosulfate), drug interactions, and safe administration. The questions emphasize practical therapeutics, toxicology, and patient safety to strengthen clinical reasoning and pharmacy practice skills. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. What is the primary mechanism of action of sodium nitroprusside?
- Inhibition of angiotensin-converting enzyme
- Blockade of beta-adrenergic receptors
- Release of nitric oxide and activation of soluble guanylate cyclase
- Calcium channel blockade
Correct Answer: Release of nitric oxide and activation of soluble guanylate cyclase
Q2. Which clinical situation is sodium nitroprusside most commonly indicated for?
- Chronic hypertension managed in outpatient clinics
- Hypertensive emergency requiring rapid blood pressure control
- Mild orthostatic hypotension
- Long-term heart failure oral therapy
Correct Answer: Hypertensive emergency requiring rapid blood pressure control
Q3. Sodium nitroprusside primarily causes dilation of which vascular beds?
- Arterioles only
- Veins only
- Both arterioles and veins (arterial and venous dilation)
- Lymphatic vessels primarily
Correct Answer: Both arterioles and veins (arterial and venous dilation)
Q4. What is the typical onset of antihypertensive effect after starting an intravenous sodium nitroprusside infusion?
- Within 24 hours
- Within hours (2–6 hours)
- Within seconds to a few minutes
- After several days of continuous infusion
Correct Answer: Within seconds to a few minutes
Q5. Metabolism of sodium nitroprusside releases which toxic ion that necessitates monitoring?
- Nitrite
- Cyanide
- Ammonium
- Sulfate
Correct Answer: Cyanide
Q6. Which antidote is considered effective for acute cyanide toxicity from nitroprusside?
- Atropine
- Hydroxocobalamin
- Calcium gluconate
- Furosemide
Correct Answer: Hydroxocobalamin
Q7. What is a commonly cited maximum infusion rate for sodium nitroprusside in µg/kg/min to avoid excessive toxicity?
- 0.05 µg/kg/min
- 0.5 µg/kg/min
- 10 µg/kg/min
- 100 µg/kg/min
Correct Answer: 10 µg/kg/min
Q8. In which condition is sodium nitroprusside use generally contraindicated or used cautiously due to risk of worsening cerebral perfusion?
- Hypokalemia
- Increased intracranial pressure or acute cerebral ischemia
- Osteoporosis
- Chronic stable angina
Correct Answer: Increased intracranial pressure or acute cerebral ischemia
Q9. Which monitoring parameter is essential during sodium nitroprusside infusion?
- Intermittent blood glucose every 24 hours
- Continuous arterial blood pressure monitoring
- Weekly liver function tests only
- Pulse oximetry only without blood pressure
Correct Answer: Continuous arterial blood pressure monitoring
Q10. How should sodium nitroprusside solutions be handled during preparation and infusion?
- Expose to bright light to activate the drug
- Protect from light and discard if discolored
- Store at room temperature in open air
- Mix with strong alkaline solutions for stability
Correct Answer: Protect from light and discard if discolored
Q11. Regarding use in pregnancy, which statement about sodium nitroprusside is most appropriate?
- Safe for routine outpatient use in pregnancy
- Contraindicated in all pregnant patients
- Use only if maternal benefits outweigh fetal risks due to potential cyanide exposure
- Preferable to oral antihypertensives for chronic management in pregnancy
Correct Answer: Use only if maternal benefits outweigh fetal risks due to potential cyanide exposure
Q12. Sodium nitroprusside decreases which of the following cardiac load parameters?
- Increases both preload and afterload
- Decreases preload but increases afterload
- Decreases both preload and afterload
- Has no effect on preload or afterload
Correct Answer: Decreases both preload and afterload
Q13. What is a common reflex cardiovascular response to rapid vasodilation with sodium nitroprusside?
- Bradycardia due to increased vagal tone
- Reflex tachycardia that may require beta-blocker therapy
- Immediate myocardial infarction in all patients
- Complete heart block
Correct Answer: Reflex tachycardia that may require beta-blocker therapy
Q14. Sodium nitroprusside should not be combined with which class of drugs due to risk of severe hypotension?
- Beta-2 agonists (inhaled)
- Phosphodiesterase-5 (PDE5) inhibitors like sildenafil
- Loop diuretics
- Topical antibiotics
Correct Answer: Phosphodiesterase-5 (PDE5) inhibitors like sildenafil
Q15. Which adverse effects are most characteristically associated with prolonged sodium nitroprusside therapy?
- Renal stone formation only
- Cyanide and thiocyanate toxicity with neurologic and metabolic effects
- Hyperglycemia and glycosuria
- Pulmonary fibrosis
Correct Answer: Cyanide and thiocyanate toxicity with neurologic and metabolic effects
Q16. Is sodium nitroprusside useful in acute pulmonary edema with severe hypertension?
- No, it is contraindicated in pulmonary edema
- Yes, it can rapidly reduce afterload and improve pulmonary edema in hypertensive crisis
- Only useful if given orally
- Only used for chronic management of pulmonary edema
Correct Answer: Yes, it can rapidly reduce afterload and improve pulmonary edema in hypertensive crisis
Q17. After stopping an infusion of sodium nitroprusside, how quickly do hemodynamic effects generally wear off?
- Effects persist for several days
- Effects wear off within minutes (usually 1–10 minutes)
- Effects are permanent
- Effects take weeks to reverse
Correct Answer: Effects wear off within minutes (usually 1–10 minutes)
Q18. In the management of acute aortic dissection, sodium nitroprusside is typically used in combination with which agent to optimize outcomes?
- ACE inhibitor alone
- Short-acting beta-blocker (e.g., esmolol) to control heart rate
- Long-acting nitrate only
- Intravenous potassium supplement
Correct Answer: Short-acting beta-blocker (e.g., esmolol) to control heart rate
Q19. Which laboratory measurement is useful for detecting accumulation from prolonged nitroprusside use?
- Serum lactate dehydrogenase only
- Plasma thiocyanate concentration
- Serum creatine phosphokinase only
- Serum bilirubin only
Correct Answer: Plasma thiocyanate concentration
Q20. What should you do if a prepared sodium nitroprusside solution appears discolored?
- Proceed with infusion; discoloration is normal
- Discard the solution and prepare a fresh, protected-from-light infusion
- Dilute further and continue
- Add vitamin C to neutralize discoloration
Correct Answer: Discard the solution and prepare a fresh, protected-from-light infusion
Q21. Compared with nitroglycerin, how does sodium nitroprusside differ in vascular selectivity?
- Nitroprusside acts predominantly on venous capacitance vessels only
- Nitroprusside produces both arterial and venous dilation, while nitroglycerin predominantly venodilation
- Both drugs have identical vascular selectivity
- Nitroglycerin is a pure arteriolar vasodilator
Correct Answer: Nitroprusside produces both arterial and venous dilation, while nitroglycerin predominantly venodilation
Q22. How can sodium nitroprusside affect coronary perfusion in patients with ischemic heart disease?
- Always improves coronary perfusion regardless of blood pressure
- It may reduce diastolic pressure and thereby decrease coronary perfusion, requiring caution
- Has no effect on coronary perfusion
- Increases diastolic blood pressure and improves perfusion
Correct Answer: It may reduce diastolic pressure and thereby decrease coronary perfusion, requiring caution
Q23. What is the recommendation for use of sodium nitroprusside in patients with renal impairment?
- No dose adjustment or monitoring is necessary
- Use with caution due to risk of thiocyanate accumulation and increased toxicity
- It is completely contraindicated in any renal impairment
- Only oral formulations are safe in renal impairment
Correct Answer: Use with caution due to risk of thiocyanate accumulation and increased toxicity
Q24. Prolonged infusions of sodium nitroprusside beyond which timeframe substantially increase the risk of cyanide/thiocyanate toxicity?
- Less than 1 hour
- Several minutes
- More than 24 hours (especially without monitoring)
- There is no time-related risk
Correct Answer: More than 24 hours (especially without monitoring)
Q25. What is the recommended route of administration for sodium nitroprusside?
- Oral tablet
- Intravenous infusion only
- Intramuscular injection
- Topical application
Correct Answer: Intravenous infusion only
Q26. Which structural feature of sodium nitroprusside explains its potential to release cyanide?
- Contains sulfate esters that release sulfate
- Has multiple cyanide (CN) moieties attached to an iron center
- Contains nitro groups that metabolize to nitrates only
- Is a pure organic nitrate without cyanide
Correct Answer: Has multiple cyanide (CN) moieties attached to an iron center
Q27. How should sodium nitroprusside dosing be adjusted in pediatric patients?
- Pediatric dosing is fixed and not weight-based
- Dosing is weight-based with careful titration and close monitoring for toxicity
- Not used in any pediatric patient under any circumstances
- Administered as a single bolus dose only
Correct Answer: Dosing is weight-based with careful titration and close monitoring for toxicity
Q28. What is the role of sodium thiosulfate in managing nitroprusside toxicity?
- Acts as a vasopressor to raise blood pressure
- Serves as a sulfur donor enabling rhodanese to convert cyanide to less toxic thiocyanate
- Neutralizes nitroprusside directly by oxidation
- Is used to chelate iron in the drug molecule
Correct Answer: Serves as a sulfur donor enabling rhodanese to convert cyanide to less toxic thiocyanate
Q29. Which clinical features are typical of thiocyanate accumulation during prolonged nitroprusside therapy?
- Gastrointestinal bleeding and hematuria
- Neurological symptoms such as confusion, tinnitus, and psychosis
- Severe hypoglycemia only
- Marked hyperkalemia only
Correct Answer: Neurological symptoms such as confusion, tinnitus, and psychosis
Q30. Which concomitant drug is commonly used to blunt reflex tachycardia caused by sodium nitroprusside?
- Furosemide
- Esmolol (short-acting beta-blocker)
- Amiodarone
- Oral nifedipine
Correct Answer: Esmolol (short-acting beta-blocker)
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