Question:medium
Which of the following is true about calcium channel blockers?
Which of the following is true about calcium channel blockers?
Show Hint
Pure arteriolar dilators trigger the baroreflex; rate-controlling CCBs do not.
Updated On: Jun 24, 2026
- Verapamil causes reflex tachycardia
- Diltiazem causes reflex tachycardia
- Nifedipine causes reflex tachycardia
- Nifedipine has a longer t1/2 than felodipine
Show Solution
The Correct Option is C
Solution and Explanation
Step 1: Think about how each agent influences heart rate through its site of action. The reflex tachycardia answer depends on which drug is the purest vasodilator with no direct cardiac slowing.
Step 2: Nifedipine, being a dihydropyridine, acts almost entirely on peripheral arterioles. The sudden vasodilation and pressure drop are sensed by carotid and aortic baroreceptors, which fire off a compensatory sympathetic surge that speeds up the heart. Hence nifedipine is classically linked with reflex tachycardia.
Step 3: By contrast, verapamil and diltiazem suppress conduction at the AV node and slow the sinus node directly. Any reflex sympathetic drive is offset by this direct cardiac depression, so they do not show reflex tachycardia, eliminating choices (a) and (b).
Step 4: Regarding pharmacokinetics, felodipine is the more vascular-selective, widely distributed agent with the longer elimination half-life. Therefore the claim that nifedipine outlasts felodipine is false, eliminating (d).
\[\boxed{\text{Nifedipine causes reflex tachycardia}}\]
Step 2: Nifedipine, being a dihydropyridine, acts almost entirely on peripheral arterioles. The sudden vasodilation and pressure drop are sensed by carotid and aortic baroreceptors, which fire off a compensatory sympathetic surge that speeds up the heart. Hence nifedipine is classically linked with reflex tachycardia.
Step 3: By contrast, verapamil and diltiazem suppress conduction at the AV node and slow the sinus node directly. Any reflex sympathetic drive is offset by this direct cardiac depression, so they do not show reflex tachycardia, eliminating choices (a) and (b).
Step 4: Regarding pharmacokinetics, felodipine is the more vascular-selective, widely distributed agent with the longer elimination half-life. Therefore the claim that nifedipine outlasts felodipine is false, eliminating (d).
\[\boxed{\text{Nifedipine causes reflex tachycardia}}\]
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