Antiarrhythmic Drugs-Overview

Dr. Fahad AzamShifa College of Medicine

Classification of drugs Mechanism of action

IA Na+ channel blockerQunidine, Procainamide

IB Na+ channel blockerLidocaine, Mexiletine

IC Na+ channel blockerFlecainide, Propafenone

II Beta receptor blockerPropanalol, Metoprolol

III K+ channel blockerAmiodarone, Sotalol,

IV Ca+ channel blockerVerapamil, Diltiazem, Nifedipine

Classification of antiarrhythmic drugs

Conduction Pathways and Velocity of Conduction

• Conduction Pathway:SA node atrial muscle AV node Purkinjee fibers Ven. Muscle

• Velocity:– Fast conducting fiber:• Purkinjee cell, Ventricular muscle, Atrial muscle

– Slow conducting fiber:• AV node, SA node

delay

Classification of drugs

Mechanism of action

IA Na+ channel blockerQunidine, Procainamide

IB Na+ channel blockerLidocaine, Mexiletine

IC Na+ channel blockerFlecainide, Propafenone

II Beta receptor blockerPropanalol, Metoprolol

III K+ channel blockerAmiodarone, Sotalol,

IV Ca+ channel blockerVerapamil, Diltiazem, Nifedipine

Intracellular Extracellular

Na Leak

K Pump

Na Pump

K Diffusion