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.

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

• • Amlodipine
• • Nifedipine
• • Felodipine
• • Nicardipine
• • Clevidipine

Most outpatient hypertension management uses: → Amlodipine

• • First-line therapy
• • Effective in Black patients
• • Often combined with ACE Inhibitors or ARBs

→ Hypertension Module

• Reduce afterload • Improve myocardial oxygen supply-demand balance

→ Anti-Anginal Module

• First-line therapy • Relieve coronary artery spasm

• • Nicardipine
• • Clevidipine

Used for rapid BP control.

• 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.

Use caution in:

• • Severe hypotension
• • Advanced aortic stenosis

Generally safe in:

• HFrEF (amlodipine acceptable)

Unlike:

• Non-DHP CCBs which may worsen systolic HF.

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

• ✔ 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