Beta adrenergic blockers – Esmolol MCQs With Answer

Introduction: Beta adrenergic blockers — Esmolol MCQs With Answer offers B. Pharm students a focused, exam-oriented review of esmolol, an ultra‑short‑acting beta1‑selective blocker used intravenously for acute rate control. This concise guide covers pharmacology, mechanism of action, pharmacokinetics (rapid hydrolysis by esterases, short half‑life), dosing, clinical indications, adverse effects, contraindications, interactions and monitoring. Keywords such as esmolol, beta blockers, beta1 selective, IV beta blocker, pharmacology, B. Pharm students, and MCQs are integrated to boost search visibility and study relevance. Clear explanations and targeted questions help reinforce core concepts and clinical application. Now let’s test your knowledge with 50 MCQs on this topic.

Q1. Which of the following best describes esmolol’s primary receptor selectivity?

• Nonselective beta antagonist blocking both β1 and β2 receptors
• Selective β1 adrenergic blocker
• Selective β2 adrenergic blocker
• Alpha-1 adrenergic blocker

Correct Answer: Selective β1 adrenergic blocker

Q2. The elimination half-life of esmolol is approximately:

• 2–4 hours
• 1–2 hours
• 9 minutes
• 24 hours

Correct Answer: 9 minutes

Q3. Esmolol is primarily metabolized by:

• CYP3A4 hepatic enzymes
• Plasma cholinesterase
• Red blood cell and tissue esterases
• Renal tubular enzymes

Correct Answer: Red blood cell and tissue esterases

Q4. A major clinical advantage of esmolol compared with longer‑acting beta blockers is:

• Oral bioavailability
• Prolonged duration of action allowing once‑daily dosing
• Rapid onset and ultra‑short duration enabling tight titration
• Greater lipid solubility for CNS penetration

Correct Answer: Rapid onset and ultra‑short duration enabling tight titration

Q5. Which indication is most appropriate for intravenous esmolol?

• Chronic hypertension maintenance therapy
• Acute supraventricular tachycardia and perioperative tachycardia control
• Long‑term heart failure outpatient therapy
• Bronchial asthma maintenance

Correct Answer: Acute supraventricular tachycardia and perioperative tachycardia control

Q6. Typical initial dosing strategy for esmolol often includes a bolus followed by infusion. A common bolus dose is:

• 5 mg
• 500 μg/kg over 1 minute
• 50 mg orally
• 2 g IV over 10 minutes

Correct Answer: 500 μg/kg over 1 minute

Q7. After the bolus, a starting infusion rate for esmolol is commonly:

• 50 μg/kg/min
• 10 mg/hour
• 1 μg/kg/min
• 500 μg/kg/min

Correct Answer: 50 μg/kg/min

Q8. Which monitoring parameter is essential during esmolol infusion?

• Glucose only
• Heart rate and blood pressure
• Serum potassium once daily
• Peak plasma drug levels

Correct Answer: Heart rate and blood pressure

Q9. Esmolol’s onset of action after IV bolus is approximately:

• 30–60 minutes
• 15–20 minutes
• 1–2 minutes
• Immediate to within a few minutes

Correct Answer: Immediate to within a few minutes

Q10. Which adverse effect is most commonly associated with esmolol?

• Severe prolonged bronchospasm in all patients
• Hypotension and bradycardia
• Renal failure due to direct toxicity
• Hyperthyroidism induction

Correct Answer: Hypotension and bradycardia

Q11. Esmolol should be used with caution or avoided in which cardiac condition?

• SVT with a narrow QRS
• Acute decompensated heart failure with cardiogenic shock
• Postoperative sinus tachycardia with stable hemodynamics
• Atrial fibrillation requiring rate control

Correct Answer: Acute decompensated heart failure with cardiogenic shock

Q12. The mechanism by which esmolol reduces heart rate is primarily due to:

• Blockade of cardiac β1 receptors leading to decreased SA and AV nodal activity
• Stimulation of vagal tone via central receptors
• Direct sodium channel blockade in ventricles
• Alpha‑1 receptor antagonism causing reflex tachycardia

Correct Answer: Blockade of cardiac β1 receptors leading to decreased SA and AV nodal activity

Q13. Esmolol is least useful for which of the following conditions?

• Acute perioperative tachycardia
• Hypertensive emergency requiring immediate heart rate control
• Long‑term oral management of chronic stable angina
• Rate control in thyrotoxic tachycardia

Correct Answer: Long‑term oral management of chronic stable angina

Q14. Compared to propranolol, esmolol has which of the following characteristics?

• Longer half‑life and oral use preferred
• Nonselective beta blockade
• Shorter half‑life and β1 selectivity
• Greater lipid solubility causing more CNS side effects

Correct Answer: Shorter half‑life and β1 selectivity

Q15. The rapid offset of esmolol is primarily beneficial when:

• A patient requires prolonged outpatient therapy
• Hemodynamic status is unpredictable and titration is needed
• There is a need for central nervous system penetration
• Treating chronic hypertension in primary care

Correct Answer: Hemodynamic status is unpredictable and titration is needed

Q16. Which laboratory measure most directly affects esmolol elimination?

• Liver CYP450 activity
• Renal creatinine clearance
• Red blood cell esterase activity
• Serum albumin concentration

Correct Answer: Red blood cell esterase activity

Q17. In overdose presenting with severe bradycardia from esmolol, the drug of choice for immediate reversal is:

• Atropine
• Propranolol
• Flumazenil
• Naloxone

Correct Answer: Atropine

Q18. Esmolol infusion is often preferred in perioperative settings because it:

• Causes marked bronchodilation
• Has minimal interaction with anesthetic agents
• Allows rapid termination if hypotension occurs
• Is administered orally

Correct Answer: Allows rapid termination if hypotension occurs

Q19. Which of the following is a potential pulmonary concern with beta blockers, even though esmolol is β1 selective?

• Bronchospasm due to partial β2 blockade at high doses
• Permanent COPD cure
• Increased surfactant production
• Direct alveolar epithelial injury

Correct Answer: Bronchospasm due to partial β2 blockade at high doses

Q20. For a patient with renal failure, dose adjustment of esmolol is generally:

• Required because esmolol is renally cleared unchanged
• Not required because esmolol is rapidly hydrolyzed by esterases
• Mandated only if creatinine clearance <30 mL/min
• Avoided entirely due to nephrotoxicity

Correct Answer: Not required because esmolol is rapidly hydrolyzed by esterases

Q21. Which drug interaction increases risk of severe bradycardia when combined with esmolol?

• Loop diuretics
• Diltiazem or verapamil (non‑dihydropyridine calcium channel blockers)
• Acetaminophen
• Short‑acting nitrates

Correct Answer: Diltiazem or verapamil (non‑dihydropyridine calcium channel blockers)

Q22. Esmolol is classified under which pregnancy risk category historically?

• Category A
• Category B
• Category C
• Category X

Correct Answer: Category C

Q23. Which monitoring consideration is important when using esmolol in diabetic patients?

• It increases fasting glucose substantially
• It can mask signs of hypoglycemia such as tachycardia
• It enhances insulin secretion
• It causes severe hyperkalemia

Correct Answer: It can mask signs of hypoglycemia such as tachycardia

Q24. The primary route of administration for esmolol in acute settings is:

• Intramuscular injection
• Oral tablet
• Intravenous infusion
• Transdermal patch

Correct Answer: Intravenous infusion

Q25. Which of the following is a contraindication to esmolol therapy?

• Sinus tachycardia requiring rate control
• Second‑ or third‑degree heart block without a pacemaker
• Acute supraventricular tachycardia
• Thyroid storm with rapid ventricular rate

Correct Answer: Second‑ or third‑degree heart block without a pacemaker

Q26. Esmolol’s chemical property that limits CNS penetration is:

• High lipid solubility
• Low molecular weight
• Low lipid solubility and polarity
• Ability to cross blood–brain barrier easily

Correct Answer: Low lipid solubility and polarity

Q27. Which statement about esmolol and hepatic impairment is correct?

• Hepatic impairment dramatically prolongs esmolol half‑life
• Esmolol clearance is independent of hepatic CYP metabolism
• Esmolol is contraindicated in any liver disease
• Esmolol is activated by the liver into an active metabolite

Correct Answer: Esmolol clearance is independent of hepatic CYP metabolism

Q28. When titrating esmolol infusion to control heart rate, the clinician should aim primarily to:

• Reduce systolic blood pressure below 80 mmHg
• Achieve target heart rate while maintaining adequate perfusion
• Maintain heart rate at exactly 50 bpm regardless of symptoms
• Increase AV conduction velocity

Correct Answer: Achieve target heart rate while maintaining adequate perfusion

Q29. Which adverse effect may occur due to abrupt withdrawal of beta blockers but is less problematic with short‑acting esmolol?

• Rebound tachycardia and hypertension
• Permanent arrhythmia induction
• Immediate renal failure
• Thyroid suppression

Correct Answer: Rebound tachycardia and hypertension

Q30. In a patient taking clonidine, initiating esmolol without proper strategy can cause:

• Enhanced clonidine analgesia
• Unopposed alpha stimulation and severe hypertension if clonidine withdrawn
• Complete protection against withdrawal effects
• Hyperglycemia due to combined metabolic effects

Correct Answer: Unopposed alpha stimulation and severe hypertension if clonidine withdrawn

Q31. Which monitoring device is most useful during esmolol infusion for arrhythmia control?

• Pulse oximeter only
• Continuous ECG monitoring
• 24‑hour Holter after stopping infusion only
• Daily chest X‑ray

Correct Answer: Continuous ECG monitoring

Q32. Esmolol reduces myocardial oxygen demand primarily by:

• Increasing myocardial contractility
• Lowering heart rate and contractility via β1 blockade
• Vasodilating coronary arteries directly
• Raising systemic catecholamine levels

Correct Answer: Lowering heart rate and contractility via β1 blockade

Q33. Which laboratory value is most useful to assess safety during prolonged esmolol infusion?

• Serum sodium every 6 hours
• Arterial blood gas for oxygenation only
• Frequent blood pressure and heart rate assessments
• Plasma esmolol concentration monitoring

Correct Answer: Frequent blood pressure and heart rate assessments

Q34. Esmolol would be least appropriate in a patient with which respiratory history?

• Mild, well‑controlled allergic rhinitis
• Severe reactive airway disease with recent bronchospasm
• Stable COPD with no recent exacerbations
• Former smoker with normal spirometry

Correct Answer: Severe reactive airway disease with recent bronchospasm

Q35. Compared to labetalol, esmolol differs in that esmolol:

• Has combined alpha and beta blockade
• Is orally active with long duration
• Is strictly IV and ultra‑short acting with β1 selectivity
• Causes more pronounced peripheral vasodilation

Correct Answer: Is strictly IV and ultra‑short acting with β1 selectivity

Q36. Which is the correct management step for esmolol‑induced hypotension?

• Increase the infusion rate immediately
• Stop or reduce the infusion and provide IV fluids and vasopressors if needed
• Administer oral beta blocker to counteract effects
• Ignore unless symptomatic

Correct Answer: Stop or reduce the infusion and provide IV fluids and vasopressors if needed

Q37. Esmolol’s rapid hydrolysis leads to which pharmacokinetic consequence?

• Accumulation with continuous infusion for days
• Minimal accumulation and quick return to baseline after stopping
• Requirement for renal dose adjustment in all patients
• Conversion to an active metabolite causing prolonged effect

Correct Answer: Minimal accumulation and quick return to baseline after stopping

Q38. In thyroid storm with severe tachycardia, esmolol is preferred because:

• It permanently treats hyperthyroidism
• It allows short‑term HR control and rapid cessation when thyroid status improves
• It stimulates thyroid hormone clearance directly
• It is effective orally for outpatient thyroid control

Correct Answer: It allows short‑term HR control and rapid cessation when thyroid status improves

Q39. Which population requires extra caution though esmolol metabolism is rapid?

• Neonates and infants due to immature esterases and hemodynamics
• Healthy young adults
• Patients with stable hypertension on oral therapy
• Patients taking vitamin supplements

Correct Answer: Neonates and infants due to immature esterases and hemodynamics

Q40. Which statement about esmolol and myocardial ischemia is correct?

• Esmolol increases myocardial oxygen demand
• Beta1 blockade can reduce ischemia by lowering heart rate and contractility
• Esmolol causes coronary vasospasm and worsens ischemia
• Esmolol is contraindicated in ischemic heart disease

Correct Answer: Beta1 blockade can reduce ischemia by lowering heart rate and contractility

Q41. A clinician wants to rapidly reverse esmolol effects during surgery due to severe hypotension. The fastest approach is to:

• Give an oral beta blocker antagonist
• Discontinue the esmolol infusion and administer IV fluids and vasopressors
• Await renal clearance
• Prescribe long‑acting beta agonists

Correct Answer: Discontinue the esmolol infusion and administer IV fluids and vasopressors

Q42. For rate control in atrial fibrillation in a monitored setting, esmolol is chosen over oral agents because it:

• Has unpredictable effects and cannot be titrated
• Provides rapid, titratable IV control with short duration if adverse effects occur
• Is effective as a single dose pill
• Increases AV nodal conduction to terminate AF

Correct Answer: Provides rapid, titratable IV control with short duration if adverse effects occur

Q43. Which statement about esmolol dosing conversions is true?

• Oral to IV dose conversion is straightforward using a 1:1 mg basis
• Esmolol has no oral formulation, so direct conversion is not applicable
• Oral esmolol is used for chronic therapy
• Transdermal esmolol has superior bioavailability

Correct Answer: Esmolol has no oral formulation, so direct conversion is not applicable

Q44. When combining esmolol with digoxin for rate control, the clinician should be aware that:

• There is potential additive bradycardia and AV block risk
• Digoxin completely antagonizes esmolol’s effect
• Combination causes immediate renal failure
• There is no interaction and monitoring is unnecessary

Correct Answer: There is potential additive bradycardia and AV block risk

Q45. Which factor does NOT significantly influence esmolol’s duration of action?

• Red blood cell esterase activity
• Infusion rate and duration
• Hepatic CYP450 polymorphisms
• Patient’s circulatory status

Correct Answer: Hepatic CYP450 polymorphisms

Q46. In an esmolol pharmacology MCQ, which statement correctly explains why it is favored in acute care?

• Because it is the most potent long‑acting beta blocker available
• Because its ultrashort half‑life allows rapid titration and safety in unstable patients
• Because it enhances catecholamine release to support blood pressure
• Because it is administered orally for quick action

Correct Answer: Because its ultrashort half‑life allows rapid titration and safety in unstable patients

Q47. Which ECG change might be seen with excessive esmolol effect?

• Sinus tachycardia
• Prolongation of PR interval and possible AV block
• ST elevation consistent with transmural infarction induced by drug
• Widening of QRS due to sodium channel blockade

Correct Answer: Prolongation of PR interval and possible AV block

Q48. When calculating an esmolol infusion for a 70 kg patient at 100 μg/kg/min, the infusion rate in μg/min is:

• 700 μg/min
• 70 μg/min
• 10,000 μg/min
• 100 μg/min

Correct Answer: 700 μg/min

Q49. Which clinical scenario exemplifies an ideal use of esmolol?

• Outpatient chronic hypertension management
• Intraoperative tachycardia requiring short‑term, titratable control
• Long‑term therapy for stable angina as a first‑line oral agent
• Bronchospasm treatment in asthma exacerbation

Correct Answer: Intraoperative tachycardia requiring short‑term, titratable control

Q50. A patient receiving esmolol infusion develops wheezing and bronchospasm. The most appropriate immediate action is:

• Increase the esmolol infusion to overcome bronchospasm
• Stop esmolol infusion and treat bronchospasm with bronchodilators
• Administer oral beta blocker to stabilize airways
• Ignore symptoms and continue monitoring only

Correct Answer: Stop esmolol infusion and treat bronchospasm with bronchodilators

G S Sachin

I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.

Mail- Sachin@pharmacyfreak.com