Antiarrhythmic Medication Classes: PTCB Exam Review
Review the Vaughan-Williams classification of antiarrhythmic drugs, key medications, and important safety considerations for the PTCB exam.
Antiarrhythmics on the PTCB Exam
Antiarrhythmic medications correct irregular heart rhythms and are classified using the Vaughan-Williams system. Understanding these classes helps pharmacy technicians identify drug interactions and safety concerns. Prepare thoroughly with our PTCB study resources.
The Vaughan-Williams Classification
Class I: Sodium Channel Blockers
Class I is subdivided into IA (procainamide, quinidine), IB (lidocaine, mexiletine), and IC (flecainide, propafenone). These drugs slow cardiac conduction by blocking sodium channels at different rates.
Class II: Beta-Blockers
Metoprolol, atenolol, and propranolol reduce heart rate and conduction through the AV node. They are commonly used for rate control in atrial fibrillation and post-myocardial infarction management.
Class III: Potassium Channel Blockers
Amiodarone (Cordarone) and sotalol (Betapace) prolong the action potential duration. Amiodarone is one of the most frequently tested medications due to its extensive side effect profile and drug interactions.
Class IV: Calcium Channel Blockers
Verapamil and diltiazem slow conduction through the AV node. They are used for supraventricular tachycardias and rate control.
Critical Safety Points
- Amiodarone can cause thyroid dysfunction, pulmonary toxicity, and photosensitivity
- Amiodarone interacts with warfarin, digoxin, and many other medications
- Sotalol requires renal dose adjustment and QTc monitoring
- Dronedarone (Multaq) is contraindicated in permanent atrial fibrillation
Test your pharmacology knowledge with our PTCB practice exam.
Ready to ace the PTCE?
Practice with 800+ flashcards, 40 mini exams, and 10 full-length PTCE simulations.
Start Free