AF AF Pharmacology & Medications 1 — Questions and Answers
Question 1: Which class of anticoagulants is preferred over warfarin for non-valvular atrial fibrillation due to a more predictable pharmacokinetic profile?
- Direct oral anticoagulants (DOACs) (Correct answer)
- Unfractionated heparin
- Aspirin
- Clopidogrel
Correct answer: Direct oral anticoagulants (DOACs)
DOACs such as apixaban, rivaroxaban, and dabigatran are preferred over warfarin for non-valvular AF due to predictable dosing, fewer drug interactions, and no routine INR monitoring.
Question 2: What is the primary goal of rate control therapy in atrial fibrillation?
- Restore sinus rhythm
- Keep resting heart rate below 110 bpm (Correct answer)
- Eliminate P waves on ECG
- Increase cardiac output above normal
Correct answer: Keep resting heart rate below 110 bpm
Rate control therapy aims to keep the resting ventricular rate below 110 bpm to reduce symptoms and prevent tachycardia-induced cardiomyopathy.
Question 3: Which beta-blocker is commonly used for rate control in AF patients with reduced ejection fraction?
- Atenolol
- Carvedilol (Correct answer)
- Propranolol
- Sotalol
Correct answer: Carvedilol
Carvedilol is a non-selective beta-blocker with alpha-blocking properties that provides rate control and has proven mortality benefit in heart failure with reduced ejection fraction.
Question 4: Amiodarone is classified as which Vaughan-Williams antiarrhythmic drug class?
- Class I
- Class II
- Class III (Correct answer)
- Class IV
Correct answer: Class III
Amiodarone is a Class III antiarrhythmic agent that primarily blocks potassium channels, prolonging the action potential duration and refractory period.
Question 5: What INR therapeutic range is targeted when using warfarin for stroke prevention in AF patients?
- 1.0–1.5
- 1.5–2.0
- 2.0–3.0 (Correct answer)
- 3.5–4.5
Correct answer: 2.0–3.0
The target INR for warfarin in AF stroke prevention is 2.0–3.0, balancing stroke reduction against bleeding risk.
Question 6: Which medication should be avoided in AF patients with Wolff-Parkinson-White (WPW) syndrome because it can accelerate conduction through the accessory pathway?
- Metoprolol
- Diltiazem
- Digoxin (Correct answer)
- Flecainide
Correct answer: Digoxin
Digoxin is contraindicated in AF with WPW because it can increase conduction through the accessory pathway, potentially causing rapid ventricular rates and ventricular fibrillation.
AF AF Pharmacology & Medications 1
Which class of anticoagulants is preferred over warfarin for non-valvular atrial fibrillation due to a more predictable pharmacokinetic profile?