Calcium channel blockers – how do they work?

Calcium channel blockers (antagonists) are commonly prescribed to treat quite a lot of cardiovascular disorders. All calcium channel blockers inhibit the L-type calcium channel in cells and are divided into two essential categories: dihydropyridines and non-dihydropyridines (Bloch and Basile, 2020). Dihydropyridines are potent vasodilators and have minimal effects on cardiac contractility and conduction. They could also be prescribed for the treatment of hypertension, chronic stable angina, vasospasm related to intracranial hemorrhage, and migraine. Nondihydropyridines inhibit the sinoatrial (SA) and atrioventricular (AV) nodes, reducing cardiac conduction and contractility (McKeever and Hamilton, 2021). They are used to treat hypertension (HTN) and tachydyrrhythmia and to scale back the myocardial demand for oxygen.

How do they work?

Calcium channel blockers increase the availability of oxygen to the guts muscle and slow the guts rate. Drugs produce these effects by blocking the slow calcium channel. This motion inhibits the influx of extracellular calcium ions through the cell membranes of smooth muscles of the guts muscle and vessels. Calcium channel blockers achieve this blockade without changing serum calcium concentrations.

This calcium blockade causes coronary arteries (and, to a lesser extent, peripheral arteries and arterioles) to dilate, reducing afterload and increasing oxygen delivery to the guts muscle.

Federal Drug Administration (FDA) approved calcium channel blockers

(Current status as of March 11, 2022)

Side Effects (Bloch and Basile, 2020)

Side effects of calcium channel blockers will vary depending on the sort and dose. Dihydropyridines may cause headache, dizziness, flushing and dose-dependent peripheral edema. Side effects of nondihydropyridines include constipation, bradycardia, and impaired cardiac output. These drugs are contraindicated in patients taking beta-blockers or in patients with heart failure with reduced ejection fraction, sick sinus syndrome, or second- or third-degree atrioventricular block. Reducing your dose may help alleviate unintended effects. Additionally, patients who cannot tolerate dihydropyridines may tolerate switching to non-dihydropyridine medications and vice versa.

Bloch, M. J., & Basile, J. (2020, June 15). Main unintended effects and safety of calcium channel blockers. .
https://www.uptodate.com/contents/major-side-effects-and-safety-of-calcium-channel-blockers

Facts and Comparisons (2022). Calcium channel blocking agents. https://online.factsandcomparisons.com/lco/action/doc/retrieve/docid/fc_dfc/5545842?cesid=36T6N4bHOhi&

McKeever, R. G., & Hamilton, R. J. (2021, July 25). Calcium channel blockers.
https://www.ncbi.nlm.nih.gov/books/NBK482473/