Calcium Channel Blocker Pharmacology

Classification and Mechanism

Verapamil is classified as a non-dihydropyridine calcium channel blocker (CCB) that specifically inhibits calcium influx through the high-voltage-activated L-type calcium channel, according to the American College of Cardiology 1
Verapamil belongs to the phenylalkylamine subclass of calcium channel blockers, which is distinct from dihydropyridines and benzothiazepines, as stated by the American Heart Association 1

Verapamil has less selectivity for vasculature compared to dihydropyridine CCBs, resulting in more pronounced effects on myocardial contractility and cardiac pacemaker function, as reported by the American College of Cardiology 1
It produces negative inotropic, chronotropic, and dromotropic effects on the heart, particularly affecting atrioventricular conduction, according to the American Heart Association 1 and the European Society of Cardiology 2

Verapamil is used in the management of angina pectoris, including vasospastic angina, as recommended by the American College of Cardiology 1
It is used to treat supraventricular tachyarrhythmias, including atrial fibrillation and flutter for rate control, as suggested by the American Heart Association 3 and the European Society of Cardiology 2

Verapamil should not be used in combination with ivabradine due to the risk of severe bradycardia, as warned by the American College of Cardiology 1
It is contraindicated in patients with significant left ventricular dysfunction, increased risk for cardiogenic shock, or second or third-degree atrioventricular block without a cardiac pacemaker, according to the American Heart Association 2
Common adverse effects include constipation, hypotension, bradycardia, and leg edema, as reported by the American College of Cardiology 1 and the British Medical Association 4