Pharmacology of Antiarrhythmic Agents
Start with the big picture
The lesson surveys Classes I–IV and miscellaneous antiarrhythmics. Class I agents block sodium channels, with IA, IB, and IC drugs differing in their effects on action-potential duration and conduction. Class II β-blockers reduce SA- and AV-node activity; Class III potassium-channel blockers prolong repolarization and QT; and Class IV non-DHP calcium-channel blockers slow AV conduction. The overview also covers adenosine, digoxin, magnesium sulfate, and ivabradine. Safety themes include torsades risk, important contraindications and interactions, renal dose adjustment for selected drugs, and amiodarone’s long half-life and toxicities. Together, these topics provide a framework for understanding drug selection and monitoring without treating classification alone as a substitute for clinical judgment.
What you'll learn
- Distinguish the Vaughan–Williams classes by their principal channel effects.
- Compare Class I subclasses by action-potential duration and conduction effects.
- Identify key clinical uses and safety concerns for selected antiarrhythmics.
- Recognize the roles of miscellaneous agents in arrhythmia management.
- Explain why renal adjustment and monitoring matter for selected drugs.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
