Antiarrhythmic Drugs Pharmacology: Master the Basics for MBBS

Question 1

In managing arrhythmias, why might a physician combine antiarrhythmic drugs? Discuss the potential benefits and challenges of this approach.

Accepted Answer

To increase effectiveness and reduce side effects by targeting multiple ion channels or mechanisms involved in arrhythmia development.

Answer

To completely eliminate the risk of proarrhythmia.

Answer

To make combination therapy the standard treatment for all arrhythmias.

Answer

To use combination therapy only in emergencies.

Question 2

Which of the following statements about the role of non-pharmacological interventions in the management of arrhythmias is true?

Accepted Answer

Non-pharmacological interventions can be equally effective as antiarrhythmic drugs in managing arrhythmias.

Answer

Catheter ablation is exclusively indicated in atrial fibrillation.

Answer

Implantable cardioverter-defibrillators (ICDs) are only used to treat patients in cardiac arrest.

Answer

Non-pharmacological interventions are always the first-line treatment for arrhythmias.

Question 3

Which of the following is the primary mechanism of action of Class I antiarrhythmic drugs?

Accepted Answer

Sodium channel blockade

Answer

Potassium channel blockade

Answer

Calcium channel blockade

Answer

Adenosine receptor activation

Question 4

Which of the following drugs is a Class III antiarrhythmic agent?

Accepted Answer

Amiodarone

Answer

Lidocaine

Answer

Verapamil

Answer

Digoxin

Question 5

Which of the following conditions is a contraindication for the use of Class II antiarrhythmic drugs?

Accepted Answer

Sick sinus syndrome

Answer

Atrial fibrillation

Answer

Ventricular tachycardia

Answer

Wolff-Parkinson-White syndrome

Question 6

What is the mechanism of action of adenosine in the treatment of supraventricular tachycardia?

Accepted Answer

Opens potassium channels

Answer

Blocks sodium channels

Answer

Stimulates alpha-adrenergic receptors

Answer

Increases intracellular calcium levels

Question 7

Which of the following antiarrhythmic drugs is associated with a risk of torsades de pointes?

Accepted Answer

Quinidine

Answer

Lidocaine

Answer

Amiodarone

Answer

Propranolol

Question 8

Which of the following is an indication for the use of an implantable cardioverter-defibrillator (ICD)?

Accepted Answer

Symptomatic ventricular tachycardia

Answer

Syncope of unknown origin

Answer

Atrial fibrillation with a rapid ventricular response

Answer

Congestive heart failure

Question 9

Which of the following is a mechanism of action of Class I antiarrhythmic drugs?

Accepted Answer

Blockage of sodium channels

Answer

Blockage of calcium channels

Answer

Prolongation of the action potential duration

Answer

Shortening of the refractory period

Question 10

Amiodarone is an antiarrhythmic drug that belongs to which class?

Accepted Answer

Class III

Answer

Class I

Answer

Class II

Answer

Class IV

Question 11

Which of the following is a potential adverse effect of digoxin?

Accepted Answer

Bradycardia

Answer

Tachycardia

Answer

Hypotension

Answer

Hypertension

Question 12

What is the primary mechanism of action of calcium channel blockers used in the treatment of arrhythmias?

Accepted Answer

Blockage of voltage-gated calcium channels

Answer

Blockage of potassium channels

Answer

Blockage of sodium channels

Answer

Prolongation of the action potential duration

Question 13

What is the primary mechanism of action of adenosine in the management of supraventricular arrhythmias?

Accepted Answer

Stimulation of adenosine receptors

Answer

Blockage of adenosine receptors

Answer

Increase in heart rate

Answer

Decrease in heart rate

Question 14

Class I antiarrhythmic drugs are known for their short duration of action. Which pharmacokinetic property explains this characteristic?

Accepted Answer

Short half-life

Answer

High protein binding

Answer

Extensive metabolism

Answer

Wide volume of distribution

Question 15

Which mechanism of action best describes amiodarone?

Accepted Answer

Multi-channel blockade

Answer

Sodium channel blockade

Answer

Potassium channel blockade

Answer

Calcium channel blockade

Question 16

How does the Vaughan-Williams classification of antiarrhythmic drugs aid in the effective treatment of arrhythmias?

Accepted Answer

It guides the selection of drugs based on their specific effects on heart rhythm.

Answer

It predicts drug effectiveness and safety based on chemical structure.

Answer

It simplifies dosing and administration of antiarrhythmic drugs.

Answer

It has minimal practical value in clinical settings.

Question 17

Which class of antiarrhythmic drugs primarily exerts their antiarrhythmic effects by blocking sodium channels?

Accepted Answer

Class I

Answer

Class IV

Answer

Class III

Answer

Class II

Question 18

Which antiarrhythmic drug is frequently used to manage atrial fibrillation with rapid ventricular response?

Accepted Answer

Digoxin

Answer

Propranolol

Answer

Flecainide

Answer

Amiodarone

Question 19

Which mechanism of action is responsible for the antiarrhythmic effects of adenosine?

Accepted Answer

Blocks AV node conduction

Answer

Inhibits calcium channels

Answer

Increases myocardial contractility

Answer

Prolongs action potential duration

Question 20

Which class of antiarrhythmic drugs prolongs the cardiac action potential duration and effective refractory period?

Accepted Answer

Class III

Answer

Class I

Answer

Class II

Answer

Class IV

Question 21

Which antiarrhythmic drug is commonly used to terminate supraventricular arrhythmias such as paroxysmal supraventricular tachycardia?

Accepted Answer

Adenosine

Answer

Verapamil

Answer

Propranolol

Answer

Amiodarone

Question 22

When selecting an antiarrhythmic drug for a patient, which factor is of primary importance?

Accepted Answer

Type of arrhythmia

Answer

Patient's age

Answer

Severity of symptoms

Question 23

Which antiarrhythmic drug has the highest risk of causing proarrhythmia?

Accepted Answer

Sotalol

Answer

Propranolol

Answer

Verapamil

Answer

Amiodarone