Pharmacological properties
Amlodipine (3-ethyl-5-methyl ester (±) -2 - [(aminomethoxy) methyl] -4- (o-chlorophenyl) -1,4-dihydro-6-methyl-3,5-pyridinedicarboxylic acid) - dihydropyridine antagonist of calcium ions (blocker of slow Ca2 + channels). Blocks the transmembrane flow of Ca2 + ions mainly into the cells of vascular smooth muscles, as well as the myocardium. It exhibits vasodilating, antihypertensive, antianginal, antispasmodic effects. The mechanism of antihypertensive action is due to a direct relaxing effect on vascular smooth muscles. Due to the slow onset of action and prolonged effect, it does not cause pronounced arterial hypotension, providing a clinically significant smooth decrease in blood pressure and its control within 24 hours when taken once a day.
Amlodipine has an antianginal effect due to the expansion of peripheral arterioles and a decrease in the load on the heart, the expansion of coronary vessels in unchanged and ischemic areas of the myocardium. Reduces the degree of hypertrophy of the left ventricular myocardium. Inhibits platelet aggregation. Increases glomerular filtration, slightly increases natriuresis and diuresis. Unlike first-generation dihydropyridine calcium antagonists, amlodipine practically does not increase the level of catecholamines in the blood plasma and does not stimulate the renin-angiotensin system.
Rapidly absorbed after oral administration. Maximum plasma concentration is reached after 6-12 hours. Absolute bioavailability is 64-80%. Amlodipine is biotransformed in the liver to form inactive metabolites. The half-life is approximately 35 hours. It is excreted in the urine both unchanged (10%) and in the form of metabolites (60%).
Indication
Ag, CHD - stable and vasospastic angina (Prinzmetal's angina).
Application
Safety and efficacy in children have not been established. For adults with angina pectoris and angina pectoris, the initial dose is 5 mg once a day, regardless of meals. If necessary, after 7-8 days, the dose is increased to the maximum - 10 mg/day. The maximum therapeutic effect develops within 8 weeks.
Contraindication
Hypersensitivity to amlodipine, arterial hypotension.
Side effects
Usually well tolerated; the most common side effects are leg swelling, headache, hypotension, drowsiness, palpitations, facial flushing, dizziness, nausea, abdominal pain, rarely - allergic skin reactions, gingival hyperplasia; with prolonged use - paresthesia and pain in the extremities.
Special instructions
In patients with impaired liver function, the half-life of the drug increases, which requires caution when selecting the daily dose. The safety of amlodipine during pregnancy and breastfeeding has not been established, therefore the drug should be prescribed only if the expected therapeutic effect for the pregnant woman or mother outweighs the potential risk to the fetus or infant.
Interactions
Amlodipine is characterized by the absence of interaction with drugs most widely used in clinical practice, including cimetidine, nonsteroidal anti-inflammatory drugs, rifampicin, etc. In case of angina pectoris, coronary heart disease, it can be used in combination with α- and β-blockers, ACE inhibitors, nitrates, and diuretics.
Overdose
A significant overdose can lead to excessive peripheral vasodilation, a pronounced and prolonged decrease in blood pressure, tachycardia. The occurrence of these symptoms requires discontinuation of the drug; the patient is given a horizontal position with raised lower extremities. Gastric lavage with a suspension of activated charcoal is indicated, support for the function of the cardiovascular system with constant monitoring of heart, lung, BCC and diuresis indicators, intravenous administration of plasma substitutes, calcium gluconate, dopamine, phenylephrine. Hemodialysis is ineffective.
Storage conditions
In a dry, dark place at a temperature not exceeding 25 °C.
