Clinician's Pocket Drug Reference 2008

Tables 239TABLE 10Antiarrhythmics: Vaughn Williams ClassificationClass I: Sodium Channel BlockadeA. Class Ia: Lengthens duration of action potential (↑ the refractory periodin atrial and ventricular muscle, in SA and AV conduction systems, andPurkinje fibers)1. Amiodarone (also class II, III, IV)2. Disopyramide (Norpace)3. Imipramine (MAO inhibitor)4. Procainamide (Pronestyl)5. QuinidineB. Class Ib: No effect on action potential1. Lidocaine (Xylocaine)2. Mexiletine (Mexitil)3. Phenytoin (Dilantin)4. Tocainide (Tonocard)C. Class Ic: Greater sodium current depression (blocks the fast inwardNa + current in heart muscle and Purkinje fibers, and slows the rate of ↑of phase 0 of the action potential)1. Flecainide (Tambocor)2. PropafenoneClass II: Beta blockerD. Amiodarone (also class Ia, III, IV)E. Esmolol (Brevibloc)F. Sotalol (also class III)Class III: Prolong refractory period via action potentialG. Amiodarone (also class Ia, II, IV)H. SotalolClass IV: Calcium channel blockerI. Amiodarone (also class Ia, II, III)J. Diltiazem (Cardizem)K. Verapamil (Calan)