]> 2026-07-31T10:04:31+00:00 WBR0401 0 en Sotalol Sotalol is a class III anti-arrhythmic that acts by blocking cardiac potassium channels. It is associated with a dose dependent prolongation of the QT interval. Verapamil Verpamil is a non-dihydropyridine calcium channel blocker, a class IV anti-arrhythmic. It has no effect on potassium channels and does not prolong the QT interval. Propafenone Propafenone is a class IC anti-arrhythmic. It acts mainly by decreasing the slope of phase 0, and has no effect on APD or QT interval. Esmolol Esmolol is a class II anti-arrythmic/β-blocker that acts by slowing conduction and decreasing the slope of phase 4. Mexiletine Mexiletine is a class IB anti-arrhythmic. Similarly to all other class I agents, it decreases the slope of phase 0. Mexiletine decreases APD, and ERP but has no effect on the QT interval. Pharmacology The mechanism of action of a novel experimental drug is under investigation. The drug is intended to treat patients with atrial and ventricular arrhythmias who cannot tolerate other therapies. After initial rat testing, the core lab determines that the active molecule acts on the trans-membrane proteins that regulates the resting membrane potential of cardiomyocytes. ECG monitoring demonstrates significant, dose-dependent increase in the QT interval in treated rats. Which of the following drugs has a mechanism of action similar to the experimental drug being evaluated? A Cardiology Vascular 2020-10-28T00:27:03Z 2459150.5187847 WBR0401