Conventional and sustained-release procainamide: update on pharmacology and clinical use.

Hemodynamic and electrophysiologic effects of procainamide, the pharmacokinetic properties of conventional and sustained-release forms of the drug, guidelines for its administration and dosage, and contraindications for and adverse effects of its use are outlined. A review of clinical studies of procainamide therapy concludes that in the treatment of ventricular arrhythmia it is comparable to other class IA drugs and generally superior to beta-blockers and to class IB drugs. For atrial arrhythmias, procainamide is usually the drug of choice when intravenous therapy is indicated; for oral prophylaxis, quinidine or the sustained-release form of procainamide is more effective than conventional formulation oral procainamide. Because procainamide is the only class I antiarrhythmic drug currently available that is commonly administered intravenously and orally, it is frequently the drug of choice for patients requiring both immediate and intermediate periods of arrhythmia control. It is often the drug of choice for initial testing with programmed electrical stimulation.