Beta-Adrenergic Blocking Agents (also known as Beta Blockers or Beta-Adrenergic Antagonists) and Calcium Channel Blockers (also known as Calcium Entry Blockers and Calcium Antagonists) are common medications in the management of hypertension, angina, and cardiac arrhythmias. Beta Blockers are named for their ability to bind to beta receptors, largely in the heart, taking the place of the patient’s own adrenergic agents.
Calcium Channel Blockers work in one of two ways. Some target the calcium channels within the heart muscle cells to slow the rate at which they create an action potential to initiate a heartbeat and diminish the strength of the contraction. Others target vascular smooth muscle to relax, decreasing blood pressure. Both have the end result of easing the strain on the heart.
Given the general depressing effect on the patient’s heart rate and blood pressure, calcium channel and beta blockers are contraindicated in cases of patients who are hypersensitive, possess an abnormally low blood pressure or heart rate, or have atrioventricular blocks, decompensated heart failure or peripheral circulatory disorders.
Beta blockers are known for their drug names ending in -olol. Examples include metoprolol and propranolol.
Calcium channel blockers are named based on their sub-class (sub-class will be explained in more detail in the next lesson):
- Dihydropyridines are known by their drug name ending in -dipine: Almodipine, Nifedipine, Nimodipine, and Felodipine.
- Nondihydropyridines have no naming pattern: Diltiazem, Verapamil, and Flunarizine.
Compendium of Pharmaceuticals and Specialties, online version (CPS). Beta-adrenergic Blocking Agents. Last Revised February 2014. © Canadian Pharmacists Association, 2015. All rights reserved.
Compendium of Pharmaceuticals and Specialties, online version (CPS). Calcium Channel Blockers. Last Revised September 2011. © Canadian Pharmacists Association, 2015. All rights reserved.