Calcium antagonists are a general term for a class of drugs whose mechanism of action is to affect calcium ion channels on the heart and large blood vessels. Most often used in the treatment of hypertension and arrhythmias, ion channels are present in the heart and blood vessels themselves and perform physiological functions by regulating ion levels inside and outside the cells. By calcium antagonists can reduce the flow of calcium outside the cell, into the cell, thus inhibiting the contraction of cardiomyocytes, while suppressing the concentration of calcium ions in the blood vessels. By lowering the patient’s blood pressure by this type of method, a certain degree of vasodilatation and inhibition of the myocardium can be achieved, thus exerting a hypotensive effect. It also reduces, or to some extent inhibits, the electrical conduction and function of the sinus and atrioventricular nodes. For patients with arrhythmias, it can lower the heart rate and play a corresponding therapeutic role.