Sympatholytics MCQs With Answer

Sympatholytics MCQs With Answer offer B. Pharm students a focused, exam-ready review of drugs that reduce sympathetic nervous system activity. This concise, keyword-rich introduction covers adrenergic blockers, alpha blockers, beta blockers, centrally acting agents, ganglionic blockers, mechanisms of action, pharmacology, clinical uses, adverse effects, contraindications, and drug interactions. Questions emphasize receptor selectivity, pharmacokinetics, therapeutic applications (hypertension, heart failure, pheochromocytoma), and emergency management, helping students build deep understanding rather than rote memorization. Each MCQ reinforces critical principles needed for prescriptions, patient safety, and rational drug choice. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. Which drug is an irreversible nonselective alpha antagonist commonly used preoperatively in pheochromocytoma?

  • Phentolamine
  • Prazosin
  • Phenoxybenzamine
  • Tamsulosin

Correct Answer: Phenoxybenzamine

Q2. Which sympatholytic acts by stimulating central alpha-2 adrenergic receptors to reduce sympathetic outflow?

  • Clonidine
  • Propranolol
  • Prazosin
  • Reserpine

Correct Answer: Clonidine

Q3. A beta-1 selective blocker preferred for patients with asthma to minimize bronchoconstriction is:

  • Propranolol
  • Metoprolol
  • Carvedilol
  • Pindolol

Correct Answer: Metoprolol

Q4. Which drug depletes norepinephrine from sympathetic nerve endings by inhibiting vesicular monoamine transporter (VMAT)?

  • Guanethidine
  • Reserpine
  • Methyldopa
  • Phentolamine

Correct Answer: Reserpine

Q5. Labetalol differs from pure beta-blockers because it also:

  • Acts as a partial beta agonist
  • Blocks alpha-1 receptors
  • Stimulates alpha-2 receptors centrally
  • Inhibits norepinephrine synthesis

Correct Answer: Blocks alpha-1 receptors

Q6. Which adverse effect is most closely associated with nonselective beta blockers like propranolol?

  • Reflex tachycardia
  • Bronchospasm in susceptible patients
  • Significant miosis
  • Urinary retention

Correct Answer: Bronchospasm in susceptible patients

Q7. Prazosin primarily lowers blood pressure by:

  • Reducing heart rate via beta-1 blockade
  • Inhibiting central sympathetic outflow
  • Causing peripheral vasodilation via alpha-1 blockade
  • Depleting norepinephrine stores

Correct Answer: Causing peripheral vasodilation via alpha-1 blockade

Q8. Which sympatholytic is a partial beta agonist with intrinsic sympathomimetic activity (ISA)?

  • Atenolol
  • Pindolol
  • Propranolol
  • Carvedilol

Correct Answer: Pindolol

Q9. Which drug is used to reverse extravasation of norepinephrine or dopamine by blocking alpha receptors?

  • Phentolamine
  • Metoprolol
  • Clonidine
  • Hexamethonium

Correct Answer: Phentolamine

Q10. Beta-blocker therapy can mask which important symptom of hypoglycemia in diabetic patients?

  • Excessive sweating
  • Tremor and palpitations
  • Hunger
  • Polyuria

Correct Answer: Tremor and palpitations

Q11. Which sympatholytic is most likely to cause orthostatic hypotension due to venous pooling from alpha-1 blockade?

  • Phenoxybenzamine
  • Methyldopa
  • Propranolol
  • Reserpine

Correct Answer: Phenoxybenzamine

Q12. Carvedilol’s cardioprotective effects in heart failure are due to combined:

  • Alpha-2 agonism and beta-2 blockade
  • Alpha-1 blockade and beta blockade
  • VMAT inhibition and alpha blockade
  • Ganglionic blockade and beta-1 selectivity

Correct Answer: Alpha-1 blockade and beta blockade

Q13. Which sympatholytic is a centrally acting prodrug converted to alpha-methylnorepinephrine in the CNS?

  • Methyldopa
  • Guanethidine
  • Prazosin
  • Hexamethonium

Correct Answer: Methyldopa

Q14. Which agent blocks nicotinic receptors at autonomic ganglia and is mainly of historical interest?

  • Hexamethonium
  • Clonidine
  • Propranolol
  • Phentolamine

Correct Answer: Hexamethonium

Q15. A major contraindication to nonselective beta-blockers is:

  • Stable angina
  • Asthma or COPD with bronchospasm
  • Essential tremor
  • Hyperthyroidism

Correct Answer: Asthma or COPD with bronchospasm

Q16. Which sympatholytic can cause drug-induced lupus-like syndrome as an adverse effect?

  • Reserpine
  • Hydralazine
  • Propranolol
  • Methyldopa

Correct Answer: Hydralazine

Q17. The mechanism by which guanethidine lowers blood pressure is primarily:

  • Alpha-1 receptor antagonism
  • Beta-1 receptor blockade
  • Inhibition of norepinephrine release from nerve endings
  • Central alpha-2 agonism

Correct Answer: Inhibition of norepinephrine release from nerve endings

Q18. Which beta-blocker has significant lipid-soluble properties and high CNS penetration, increasing risk of sleep disturbances?

  • Atenolol
  • Metoprolol
  • Propranolol
  • Nadolol

Correct Answer: Propranolol

Q19. In the presence of alpha blockade, administration of epinephrine causes which response (epinephrine reversal)?

  • Enhanced vasoconstriction
  • Marked bradycardia only
  • Net vasodilation and hypotension
  • No change in blood pressure

Correct Answer: Net vasodilation and hypotension

Q20. Which sympatholytic is most appropriate for treating benign prostatic hyperplasia by relaxing smooth muscle in the prostate?

  • Prazosin
  • Tamsulosin
  • Propranolol
  • Clonidine

Correct Answer: Tamsulosin

Q21. Which lab abnormality can occur with nonselective beta-blockers due to inhibited lipolysis?

  • Hyperkalemia
  • Elevated LDL cholesterol
  • Hypoglycemia unawareness and impaired recovery
  • Increased HDL

Correct Answer: Hypoglycemia unawareness and impaired recovery

Q22. Abrupt withdrawal of beta-blockers can precipitate which complication?

  • Hypotension and bradycardia
  • Rebound tachycardia and angina
  • Persistent bronchospasm relief
  • Enhanced insulin sensitivity

Correct Answer: Rebound tachycardia and angina

Q23. Which sympatholytic is useful for hypertensive emergencies in pregnancy due to safe profile?

  • Methyldopa
  • Propranolol
  • Reserpine
  • Phenoxybenzamine

Correct Answer: Methyldopa

Q24. Which statement about alpha-2 agonists like clonidine is true?

  • They increase sympathetic outflow
  • They cause peripheral alpha-1 mediated vasoconstriction exclusively
  • They reduce norepinephrine release via presynaptic receptors
  • They irreversibly block alpha receptors

Correct Answer: They reduce norepinephrine release via presynaptic receptors

Q25. Which agent is contraindicated in patients with pheochromocytoma unless alpha blockade is established first?

  • Beta-blocker alone
  • Phenoxybenzamine
  • Phentolamine
  • Clonidine

Correct Answer: Beta-blocker alone

Q26. Which pharmacodynamic property explains why atenolol is less likely to cause CNS side effects than propranolol?

  • Greater intrinsic sympathomimetic activity
  • Lower lipid solubility and less blood-brain barrier penetration
  • Irreversible receptor binding
  • Stronger alpha-1 antagonism

Correct Answer: Lower lipid solubility and less blood-brain barrier penetration

Q27. Which sympatholytic is preferred for treating hypertensive patients with concomitant benign prostatic hyperplasia because it improves urinary flow?

  • Prazosin
  • Propranolol
  • Methyldopa
  • Reserpine

Correct Answer: Prazosin

Q28. Which agent is an alpha-1 selective antagonist with minimal effect on ejaculation compared to nonselective agents?

  • Tamsulosin
  • Phenoxybenzamine
  • Phentolamine
  • Clonidine

Correct Answer: Tamsulosin

Q29. Which statement best describes pindolol’s clinical implication?

  • Its ISA makes it ideal for acute myocardial infarction management
  • ISA may reduce the degree of bradycardia in resting patients
  • ISA causes irreversible beta blockade
  • ISA enhances bronchoconstriction dramatically

Correct Answer: ISA may reduce the degree of bradycardia in resting patients

Q30. Which drug interaction is important to monitor when a patient on sympatholytics receives epinephrine during surgery?

  • Alpha blockade may enhance vasoconstrictive response to epinephrine
  • Beta blockade may blunt tachycardia but unmask alpha-mediated hypertension
  • Central alpha-2 agonists potentiate epinephrine action
  • VMAT inhibitors increase epinephrine synthesis

Correct Answer: Beta blockade may blunt tachycardia but unmask alpha-mediated hypertension

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