Dihydropyridine Calcium Channel Blockers
Dihydropyridine Calcium Channel Blockers (DHP CCBs) are potent arterial vasodilators that reduce systemic vascular resistance (SVR) by blocking L-type calcium channels in vascular smooth muscle.
They are primarily used for:
• Hypertension • Stable angina • Vasospastic (Prinzmetal) angina
DHP CCBs primarily affect blood vessels, not cardiac conduction.
Mechanism of Action
DHP CCBs:
• Block L-type calcium channels in vascular smooth muscle • Decrease intracellular calcium • Cause arteriolar vasodilation
Net Effects:
• ↓ Systemic vascular resistance (afterload) • ↓ Blood pressure • Mild reflex ↑ heart rate (possible)
Minimal direct effect on: • SA node • AV node • Cardiac contractility
Contrast with: • Non-Dihydropyridine Calcium Channel Blockers
Common DHP CCBs
Indications
Hypertension
- • First-line therapy
- • Effective in Black patients
- • Often combined with ACE Inhibitors or ARBs
Stable Angina
Vasospastic (Prinzmetal) Angina
• First-line therapy • Relieve coronary artery spasm
Hypertensive Emergency (IV agents)
Adverse Effects
• Peripheral edema (dose-dependent) • Flushing • Headache • Reflex tachycardia (short-acting agents) • Gingival hyperplasia (rare)
Edema is due to preferential arteriolar dilation without venous dilation.
Adding a RAAS blocker may reduce edema.
Contraindications / Cautions
Use caution in:
- • Severe hypotension
- • Advanced aortic stenosis
Generally safe in:
• HFrEF (amlodipine acceptable)
Unlike:
• Non-DHP CCBs which may worsen systolic HF.
DHP vs Non-DHP Summary
DHP CCBs:
- • Vascular selective
- • Strong BP reduction
- • Minimal conduction effect
Non-DHP CCBs:
- • Affect SA/AV node
- • Reduce heart rate
- • Used in arrhythmias
See: → Non-DHP Calcium Channel Blockers
Clinical Pearls
- ✔ Potent arteriolar vasodilators
- ✔ First-line for hypertension
- ✔ Excellent in Black patients
- ✔ Peripheral edema is common
- ✔ Safe in HFrEF (amlodipine)
- ✔ Do not use short-acting nifedipine in hypertensive emergencies
Related:
→ Calcium Channel Blockers Overview → Hypertension Module → Anti-Anginal Module → Return to Cardiovascular Modules
