What should we expect from the next generation of antiarrhythmic drugs?
Five drugs currently constitute approximately 70% of the world market for antiarrhythmic medications. Since the publication of studies documenting that certain Class I drugs may increase mortality in high-risk postinfarction patients, basic science and clinical studies have focused on Class III antiarrhythmic drugs. However, drugs that prolong repolarization and cardiac refractoriness are sometimes associated with potentially lethal torsades de pointes. Amiodarone, a multichannel blocker, may be the exception to this observation, but it nevertheless fails to reduce total mortality compared with placebo in high-risk patients following myocardial infarction. However, Class III agents remain the focus of drug development efforts because they lack the negative hemodynamic effects, affect both atrial and ventricular tissue, and can be administered as either parenteral or oral preparations. Developers of newer antiarrhythmic agents have focused on identifying antiarrhythmic medications with
