Calcium channel blockers (antagonists) are commonly prescribed to treat a variety of cardiovascular disorders. All calcium channel blockers inhibit the L-type calcium channel within cells and are divided into two major categories, either dihydropyridines or non-dihydropyridines (Bloch & Basile, 2020). Dihydropyridines are strong vasodilators and have minimal effect on cardiac contractility or conduction. They may be prescribed to treat hypertension, chronic stable angina, post-intracranial hemorrhage associated vasospasm, and migraines. The non-dihydropyridines inhibit the sinoatrial (SA) and atrioventricular (AV) nodes, decreasing cardiac conduction and contractility (McKeever & Hamilton, 2021). They are used to treat hypertension (HTN) and tachydysrhythmias and to decrease myocardial oxygen demand.
How do they work?
Calcium channel blockers increase the myocardial oxygen supply and slow the heart rate. The drugs produce these effects by blocking the slow calcium channel. This action inhibits the influx of extracellular calcium ions across both myocardial and vascular smooth muscle cell membranes. Calcium channel blockers achieve this blockade without changing serum calcium concentrations.
No calcium = dilation
This calcium blockade causes the coronary arteries (and, to a lesser extent, the peripheral arteries and arterioles) to dilate, decreasing afterload and increasing myocardial oxygen supply.
Federal Drug Administration (FDA) Approved Calcium Channel Blockers
(Current as of March, 11, 2022)
Calcium Channel Blockers
(Facts and Comparisons, 2020) |
| Generic Name |
Brand Name |
FDA Approved Indications |
| Amlodipine |
Katerza, Norvasc |
Chronic stable angina, HTN, vasospastic angina |
| Clevidipine |
Cleviprex |
HTN |
| Diltiazem |
Cardizem CD, Cartia XT, Dilt-XR, Matzim, Taztia XT, Tiadylt ER, Tiazac |
Atrial fibrillation/flutter, chronic stable angina, HTN, paroxysmal supraventricular tachycardia (PSVT), supraventricular tachycardia (SVT), vasospastic angina |
| Felodipine |
N/A |
HTN |
| Isradipine |
N/A |
HTN |
| Levamlodipine |
Conjupri |
HTN |
| Nicardipine |
Cardene IV |
Chronic stable angina, HTN |
| Nifedipine |
Procardia XL |
Chronic stable angina, HTN, |
| Nimodipine |
Nymalize |
Subarachnoid hemorrhage |
| Nisoldipine |
Sular |
HTN |
| Verapamil |
Verelan |
Atrial fibrillation/flutter, chronic stable angina, HTN, PSVT, vasospastic angina, unstable angina |
Side Effects (Bloch & Basile, 2020)
Adverse effects of calcium channel blockers will vary with the type and dose. Dihydropyridines may cause headache, lightheadedness, flushing, and dose-dependent peripheral edema. Side effects of non-dihydropyridines include constipation, bradycardia, and worsening cardiac output. These drugs are contraindicated in patients taking beta blockers or who have heart failure with reduced ejection fraction, sick sinus syndrome, and second- or third-degree atrioventricular block. Decreasing the dose may help mitigate side effects. In addition, patients who don’t tolerate dihydropyridines may tolerate a switch to non-dihydropyridines and vice versa.
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