💊 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).