Various calcium antagonists bind to calcium channels in the cardiac and vascular smooth muscle cell membranes in their own different ways, blocking the inward flow of calcium ions and reducing intracellular calcium ion concentrations. Changes in intracellular calcium concentration can affect the coarse and fine myofilament gliding in cardiac and vascular smooth muscle cells, producing smooth muscle contraction and diastole. Thus, calcium ions play a pulley role in cardiac and vascular smooth muscle cells. When the intracellular calcium ion concentration decreases, the smooth muscle relaxes, the peripheral vascular resistance decreases, and the coronary arteries dilate, producing a hypotensive, anti-anginal effect. Conversely, when the concentration of calcium ions in cardiac muscle and vascular smooth muscle cells increases, it will cause vasoconstriction and increase blood pressure. It is from this point of action that calcium antagonists achieve the purpose of lowering blood pressure. These drugs have a significant hypotensive effect on patients with grade 1, 2 and 3 hypertension, and the higher the blood pressure, the more pronounced the effect, without causing postural hypotension and hypotensive reactions, and without reducing normal blood pressure, which is medically called “physiological hypotension”. According to the 2003 European Guidelines for the Treatment of Hypertension, calcium antagonists can be used in patients with general hypertension (without cardiac, cerebral or renal comorbidities), but they are also recommended for hypertension with angina pectoris, peripheral vascular disease and the elderly, as well as hypertensive patients with systolic hypertension and reduced glucose tolerance. Recent clinical studies have reaffirmed the good antihypertensive effect and tolerability of calcium antagonists and their ability to improve angina and prevent the progression of atherosclerosis. Currently, there are three classes of calcium antagonists commonly used in clinical practice: (1) dihydropyridines, mainly nifedipine, nicardipine, felodipine, amlodipine, etc.; (2) diltiazem, including diltiazem, etc.; and (3) benzalkamines, represented by verapamil. The effects of these three classes of drugs in the blood vessels and heart are shown in the figure. Comparison of the effects of the three classes of calcium antagonists