Calcium channel blockers are primarily used in the management of cardiovascular disease. Voltage-gated calcium channels are present in myocardial cells, cells of the conduction system and those of the vascular smooth muscle. The various types of calcium channel blockers have varying effects on these three areas and it is therefore important to differentiate their uses and actions.
| Examples | Indications & notes | Side-effects and cautions |
|---|---|---|
| Verapamil | Angina, hypertension, arrhythmiasHighly negatively inotropicShould not be given with beta-blockers as may cause heart block | Heart failure, constipation, hypotension, bradycardia, flushing |
| Diltiazem | Angina, hypertensionLess negatively inotropic than verapamil but caution should still be exercised when patients have heart failure or are taking beta-blockers | Hypotension, bradycardia, heart failure, ankle swelling |
| Nifedipine, amlodipine, felodipine(dihydropyridines) | Hypertension, angina, Raynaud'sAffects the peripheral vascular smooth muscle more than the myocardium and therefore do not result in worsening of heart failure but may therefore cause ankle swellingShorter acting dihydropyridines (e.g. nifedipine) cause peripheral vasodilation which may result in reflex tachycardia | Flushing, headache, ankle swelling |