Amlodipine - a substance belonging to a group of medicines called Calcium channel blockers (or calcium channel blockers). Chemically, amplodypin is a dihydropyridine derivative with a long duration of action. The long-acting dihydropyridine derivatives, along with amlodipine, also include felodipine, lacidipine, and nilwadipine. According to the guidelines of the Polish Association of Arterial Hypertension of 2011, long-acting dihydropyridine derivatives are the first-line drug in the treatment of people with hypertension in the elderly, patients with asthma and patients with isolated systolic hypertension.
The effect of amlodipine, like other calcium antagonists, is blocking calcium channels. Calcium channels are special structures in the cell membrane that allow the inflow of calcium ions into the cell from the extracellular space or from intracellular stores. Increasing the intracellular calcium concentration is necessary for the contraction of muscle cells, including cardiac muscle and smooth muscle in the walls of blood vessels. Amlodipine acts mainly on peripheral blood vessels and to a lesser extent on cardiac muscle cells. By inhibiting the inflow of calcium ions, it causes the reduction of smooth muscle vasodilation and vasodilatation, which has the direct effect of reducing blood pressure. Amlodipine is characterized by an even action, does not cause a sudden reduction in blood pressure and does not significantly affect the strength of myocardial contraction. Enlargement of peripheral arterioles reduces peripheral vascular resistance, which relieves the heart (it reduces energy consumption by the myocardium and its oxygen demand). Coronary arteries are also likely to expand, which increases oxygen transport to the myocardium, also in patients with vasospastic angina (Prinzmetal).
Amlodipine is used to relieve the symptoms of angina pectoris and as a medicine for lowering blood pressure. The effect of amlodipine in patients with angina pectoris, exercise tolerance increases (the time to angina pain increases during exercise) and the incidence and severity of angina pains decreases. The clinical condition of patients with angina pectoris improves and Nitroglycerin consumption decreases. In patients with hypertension, taking once daily provides a clinically significant reduction in blood pressure, both standing and lying, for 24 hours. The effect of action of amlodipine appears slowly, so it does not cause sudden hypotension. To obtain a stationary concentration of amlodipine in the blood requires 7.-8. days of daily use.
Currently on the market in Poland there are several preparations containing amlodipine, the first of which was Norvasc from Pfizer introduced to treatment in 1992.