Drugs-- Antiarrhythmics ======================= Drugs after MI, Quinidine for atrial fib: þ Antiarrhythmic Groups I moricizine IA quinidine (increase QT) procainamide (Pronestyl)** disopyramide (Norpace) IB lidocaine (Xylocaine) phenytoin (Dilantin) tocainide mexiletine IC flecainide encainide (and MODE and ODE metabolites) propafenone II propanolol (Inderal) (beta blockers) esmolol acebutolol III bretylium amiodarone sotalol IV verapamil digoxin (Lanoxin) adenosine (Adenocard) **Criteria for stopping IV procainamide: - dysrhythmia stops or converts - hypotension - QRS widens by 50% - total of 1 g dosage (or 18 mg/kg) (Schwartz 3E p 156)