Calcium Channel Blockers (Mechanism of Action)
💊 Calcium channel blockers (CCBs) are used in the treatment of many cardiovascular conditions including hypertension and angina. They are divided into subclasses, non-dihydropyridines, and dihydropyridines and differ by their pharmacokinetic properties, clinical uses, response, and selectivity.
💊 The name of this class, calcium channel blockers, hints at its mechanism of action – inhibits the entry of calcium into cells of the cardiac and peripheral vascular smooth muscles.
🗒️ Calcium entry into L-type channels of cardiac and peripheral vascular cells is needed for them to contract or constrict more strongly.
🗒️ By blocking calcium entry, calcium channel blockers cause:
👉🏻 peripheral vascular smooth muscle relaxation (decreases blood pressure)
👉🏻 decreased myocardial contractility (decrease myocardial demand making them effective in angina)
👉🏻 decrease heart rate and conduction velocity (useful in arrhythmias).