Indications of Individual Calcium Channel Blockers (CCBs)

Classification

Non-Dihydropyridines (Heart-Selective)

Verapamil

• Hypertension - long-acting formulations used as antihypertensive agents
• Angina pectoris - both vasospastic (Prinzmetal/variant) and exertional angina
• Supraventricular tachyarrhythmias (SVT) - slows AV nodal conduction; terminates re-entrant SVT and provides rate control in atrial flutter/fibrillation
• Rate control in atrial fibrillation/flutter - via negative chronotropic/dromotropic effects
• Hypertrophic cardiomyopathy (HCM) - reduces outflow tract obstruction; also used in asymptomatic HCM mutation carriers (promising early results)
• Migraine prophylaxis - second-choice agent
• Cluster headache prophylaxis - considered a primary option

Diltiazem

• Hypertension - especially oral long-acting formulations
• Angina - both variant (vasospastic) and stable exertional angina
• Rate control in atrial fibrillation/flutter - IV or oral
• SVT - terminates AV nodal re-entrant tachycardias (IV formulation)
• HCM (asymptomatic carriers) - early clinical data (Goodman & Gilman)

Verapamil and diltiazem are contraindicated with concurrent beta-blockers due to risk of complete AV block and severe ventricular depression. Also contraindicated in decompensated heart failure and pre-excitation syndromes (WPW) with AF.

Dihydropyridines (Vascular-Selective)

Nifedipine

• Hypertension - only long-acting (SR/XL) formulations are indicated; short-acting capsules are not indicated for hypertension and may worsen ischemic events
• Variant (Prinzmetal) angina - first-line; effective in ~90% of patients
• Raynaud phenomenon - reduces frequency/severity of attacks
• Preterm labor (tocolysis) - widely used off-label
• Esophageal motility disorders - reduces lower esophageal sphincter (LES) pressure; used in achalasia/diffuse esophageal spasm

Amlodipine

• Hypertension - preferred long-acting DHP; once-daily dosing
• Stable, vasospastic, and chronic stable angina
• Coronary artery disease (CAD) without heart failure
• Note: Causes less reflex tachycardia than nifedipine due to slower onset

Felodipine

• Hypertension - highly vascular-selective; less negative inotropic effect
• Stable angina (adjunctive)

Nicardipine

• Hypertension - including hypertensive emergencies (IV formulation)
• Angina

Clevidipine

• Hypertensive emergencies - rapid-onset IV agent; titrated for perioperative BP control

Nimodipine

• Subarachnoid hemorrhage (SAH) - FDA-approved to reduce neurological deficits from cerebral vasospasm; improves outcome and may reduce cerebral infarction
• Crosses the blood-brain barrier due to its lipophilic nature

Nisoldipine / Isradipine

• Hypertension - long-acting oral antihypertensives

Summary Table

Key Clinical Points

1. Only DHPs are safe in heart failure - verapamil and diltiazem are contraindicated in HF with reduced ejection fraction due to their negative inotropic effects.
2. Short-acting nifedipine is contraindicated in hypertension - it causes reflex tachycardia and may increase ischemic events.
3. DHPs + beta-blockers can be safely combined (suppresses reflex tachycardia); verapamil/diltiazem + beta-blockers are contraindicated (additive AV block).
4. Nimodipine is unique - its CNS indication (SAH) distinguishes it from all other CCBs.
5. Verapamil is the most constipating CCB and the most likely to cause bradycardia.