Clinical pharmacology of old and new antiarrhythmic drugs.

The number of antiarrhythmic drugs available in the United States is increasing, with the discovery of antiarrhythmic properties of drugs previously marketed for other indications (phenytoin, imipramine) and the development of several new drugs, many of which are likely to become commercially available in the next 5 years. The currently available drugs and several promising investigational drugs are reviewed in this report. Their optimal use is dependent on an understanding of their electropharmacologic effects, pharmacokinetics, drug interactions, and clinical pharmacology. Such use may allow better attempts to reduce arrhythmia-related death and morbidity.