Calcium Channel Blockers Study Questions and Correct Answers

What is the ion that is important for the depolarization of the nodal cell? Ca++ What are the potential effects of CCBs? 1) Reduce cardiac Automaticity 2) Reduce AV nodal conduction 3) Cause vasodilation What are the three main chemical classes of CCBs? 1) Phenylalkylamines 2) Benzothiazepines 3) 1,4-Dihydropyridines What phase of the ventricular action potential is Ca++ most important for? Plateau/ phase II Plays a role in the contraction of ventricles What chemical class does *Verapamil* belong to? Phenylalkylamines What chemical class does *Diltiazem* belong to? Benzothiazepines What chemical class do *Nifepipine* & *Amlodipine* belong to? 1,4-Dihydropyridines Which two prototypical drugs have profiles that are very similar to each other but are in different chemical classes? *Verapamil* & *Diltiazem* What are the therapeutic uses of CCBs? 1) Angina Pectoris 2) HTN 3) Treatment of supraventricular arrhythmias such as: A. Flutter, A. Fib, Paroxysmal SVT What type of Ca++ channel do CCBs block? L-Type Ca++ Channel (voltage gated channel) What CCB/CCBs targets cardiac cells? *Verapamil* & *Diltiazem* Use-dependent binding What CCB/CCBs targets smooth muscle cells? *Nifepipine* Voltage-dependent binding