Dihydropyridine calcium channel blockers vs Non-dihydropyridine calcium channel blockers
How to tell Dihydropyridine calcium channel blockers and Non-dihydropyridine calcium channel blockers apart when a board question makes them look alike.
Dihydropyridines (-dipine): vascular, cause edema and reflex tachycardia; non-dihydropyridines (verapamil, diltiazem): cardiac, slow the AV node.
Side by side
Amlodipine or nifedipine pattern with arteriolar vasodilation, flushing, headache, ankle edema, and possible reflex tachycardia.
Verapamil or diltiazem pattern with AV nodal slowing, bradycardia, constipation, and possible worsening systolic heart failure.
Preferential vascular smooth muscle calcium channel blockade lowers systemic vascular resistance.
More cardiac calcium channel blockade slows AV nodal conduction and decreases contractility.
Peripheral edema without AV block supports a dihydropyridine pattern.
Bradycardia, AV block, or constipation supports a non-dihydropyridine pattern.
The trap
Both are calcium channel blockers, but their target tissue drives very different adverse effects.
The repair move
For calcium channel blockers, decide whether the stem is describing vessel dilation or AV nodal slowing.
Try a free question
CoreA patient with hypertension starts amlodipine and later develops ankle edema and flushing without AV block. Which calcium channel blocker subgroup best explains the presentation?
Show answer and explanation
Answer: A. Dihydropyridine calcium channel blocker. Dihydropyridines primarily vasodilate arterioles, causing edema, flushing, headache, and possible reflex tachycardia.
Why the other choices are tempting
- B. Non-dihydropyridines more strongly depress AV nodal conduction and contractility.
- C. Class III antiarrhythmics prolong repolarization rather than causing classic arteriolar edema.
- D. ACE inhibitors cause RAAS blockade effects such as cough, hyperkalemia, and angioedema risk.
- E. Loop diuretics cause strong diuresis with electrolyte loss and ototoxicity risk.
Flashcards
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What is the fastest separator for Dihydropyridine calcium channel blockers vs Non-dihydropyridine calcium channel blockers?
Dihydropyridines (-dipine): vascular, cause edema and reflex tachycardia; non-dihydropyridines (verapamil, diltiazem): cardiac, slow the AV node.
What clue should make you choose Dihydropyridine calcium channel blockers?
Amlodipine or nifedipine pattern with arteriolar vasodilation, flushing, headache, ankle edema, and possible reflex tachycardia.
Quick answers
What is the fastest way to tell Dihydropyridine calcium channel blockers from Non-dihydropyridine calcium channel blockers?
Dihydropyridines (-dipine): vascular, cause edema and reflex tachycardia; non-dihydropyridines (verapamil, diltiazem): cardiac, slow the AV node.
What is the key clue for Dihydropyridine calcium channel blockers?
Amlodipine or nifedipine pattern with arteriolar vasodilation, flushing, headache, ankle edema, and possible reflex tachycardia.
What is the key clue for Non-dihydropyridine calcium channel blockers?
Verapamil or diltiazem pattern with AV nodal slowing, bradycardia, constipation, and possible worsening systolic heart failure.
What is the common trap with Dihydropyridine calcium channel blockers vs Non-dihydropyridine calcium channel blockers?
Both are calcium channel blockers, but their target tissue drives very different adverse effects.