Related Experiment Video
Updated: Aug 14, 2026

Contractions of Human-iPSC-derived Cardiomyocyte Syncytia Measured with a Ca-sensitive Fluorescent Dye in Temperature-controlled 384-well Plates
Published on: October 18, 2018
Class IB antiarrhythmic drugs: tocainide, mexiletine, and moricizine
Abstract:
Tocainide, mexiletine and moricizine belong to class IB of Vaughan Williams system of classification of antiarrhythmic drugs. Mexiletine and tocainide have little or no effect on Phase 0 of action potential and conduction velocity. Their principal effect is to shorten the action potential duration. Moricizine does not fit precisely into the Vaughan Williams system of classification, but has been categorized with class IB agents because in vitro its effects are similar to those of lidocaine. In this article, the pharmacokinetics, electrophysiologic effects, and clinical uses of these three agents are reviewed.
Related Concept Videos
Antiarrhythmic Drugs: Class I Agents as Sodium Channel Blockers
Class 1A Antiarrhythmic Drugs: These drugs work by moderately blocking sodium channels,...
Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers
Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers
Antiarrhythmic Drugs: Class IV Agents as Calcium Channel Blockers
Verapamil, a calcium channel blocker, inhibits calcium movement across myocardial cell membranes and vascular smooth muscle. This results in the dilation of coronary and...
Antiepileptic Drugs: Sodium Channel Blockers
Sodium channel blockers modulate ion channels, particularly voltage-gated sodium channels. They block only sodium ion movement.
Among the most commonly prescribed antiepileptic drugs are...
Antiepileptic Drugs: Potassium Channel Activators
Ezogabine has gained approval as an adjunctive treatment...

