Rapid Review·Cardiovascular
Select any text to highlight it or add a note.
PHARMACOLOGY
T1Must knowCalcium Channel Blockers, Antianginal Therapy & Ranolazine
FA P323-324
Focus on
Two CCB families with opposite tissue selectivity, the antianginal grid, and the antianginal that changes neither rate nor pressure.
Key takeaways
Two families, split by where they act
Dihydropyridines act on vascular smooth muscle
amlodipine, clevidipine, nicardipine, nifedipine, nimodipine.Nondihydropyridines act on the heart
diltiazem and verapamil.Mechanism
block voltage-dependent L-type calcium channels of cardiac and smooth muscle, reducing contractility. Skeletal muscle is untouched, because its ryanodine receptor opens directly without a calcium influx.Selectivity gradients, worth reading as one line each
- Vascular smooth muscle: amlodipine = nifedipine > diltiazem > verapamil.
- Heart: verapamil > diltiazem > amlodipine = nifedipine.
Dihydropyridine uses, nimodipine excepted
hypertension, angina including vasospastic angina, and Raynaud phenomenon.- Nimodipine is for subarachnoid hemorrhage, where it prevents delayed cerebral ischemia.
- Nicardipine and clevidipine are the IV agents for hypertensive urgency or emergency.
Nondihydropyridine uses
hypertension, angina, rate control in atrial fibrillation and flutter, and prevention of nodal arrhythmias.Adverse effects
- Both: gingival hyperplasia.
- Dihydropyridine: peripheral edema, flushing, dizziness.
- Nondihydropyridine: cardiac depression, AV block, constipation, and hyperprolactinemia with verapamil.
| Feature | Dihydropyridines | Nondihydropyridines |
|---|---|---|
| Drugs | Amlodipine, clevidipine, nicardipine, nifedipine, nimodipine | Diltiazem, verapamil |
| Acts on | Vascular smooth muscle | Heart |
| Main use | Hypertension, angina, Raynaud | Rate control in AF and flutter, nodal arrhythmias |
| Adverse | Peripheral edema, flushing, dizziness | Cardiac depression, AV block, constipation, hyperprolactinemia (verapamil) |
| Shared adverse | Gingival hyperplasia | Gingival hyperplasia |
| Drug | Unique use |
|---|---|
| Nimodipine | Subarachnoid hemorrhage, preventing delayed cerebral ischemia |
| Nicardipine, clevidipine | Hypertensive urgency or emergency, given IV |
| Amlodipine, nifedipine | Hypertension, angina, Raynaud |
The antianginal grid
The goal
lower myocardial oxygen consumption by reducing one or more of its determinants: end-diastolic volume, blood pressure, heart rate, and contractility.Where the CCBs fit
nondihydropyridine CCBs are similar to beta-blockers in their antianginal effect, which is why they substitute when beta-blockade is contraindicated.| Component | Nitrates | Beta-blockers | Both together |
|---|---|---|---|
| End-diastolic volume | Falls | Rises | No change or falls |
| Blood pressure | Falls | Falls | Falls markedly |
| Contractility | Rises, by reflex | Falls | Little or no change |
| Heart rate | Rises, by reflex | Falls | No change or falls |
| Ejection time | Falls | Rises | Little or no change |
| Myocardial O2 consumption | Falls | Falls | Falls the most |
Ranolazine
Mechanism
inhibits the late phase of the inward sodium current, lowering diastolic wall tension and oxygen consumption.The point of it
it does NOT affect heart rate or blood pressure, which is exactly what makes it useful once beta-blockers and nitrates have run out, or when the patient is hypotensive.Use
refractory angina. Adverse: constipation, dizziness, headache, nausea, QT prolongation.Which dihydropyridine shows up outside cardiology, and for what?
Nimodipine, for subarachnoid hemorrhage: it prevents the delayed cerebral ischemia of vasospasm rather than treating blood pressure.
How it's tested
Nitrates and beta-blockers are combined precisely because their reflexes cancel: nitrates trigger reflex tachycardia and increased contractility, which beta-blockade suppresses, while beta-blockers raise end-diastolic volume, which nitrates lower. Reading the grid column by column is the fastest way to answer any "what happens to X" question. Nimodipine is the dihydropyridine that shows up outside cardiology, for subarachnoid hemorrhage rather than hypertension. Ranolazine is the antianginal that works without touching heart rate or blood pressure, which is exactly why it is the answer when a stem says the patient is already maximally beta-blocked or is hypotensive.
Go deeper
First Aid 2026 — CV/Pharmacology (p.323-324) · B&B — Calcium channel blockers; ranolazine · Mehlman — HY Cardio (DHP vs non-DHP, rate control)
Flashcards for this page
Card 1 of 5 · try-out only, nothing is saved
(...) in blood pressure
(...) in MVO2
You just read one page of 944
The rest of Step 1, written exactly like this.
Rapid Review is the reading layer of a full Step 1 platform: a schedule fitted to your exam date, flashcards for every page, and a mentor a message away.
Every Step 1 system
Written the same way: what to know, how it’s tested, where to go deeper.
A plan built to your exam date
Tell us when you sit, and the schedule fits the whole library and your question bank to it.
Flashcards for every page
Ready-made spaced-repetition decks linked to each topic, so nothing you read gets forgotten.
