Description of the medicine: Verapamil (Verapamilum)
VERAPAMILUM *. 5 - [(3, 4-Dimethoxyphenethyl) -methylamino] -2- (3,4-dimethoxyphenyl) 2-isopropylvaleronitrile hydrochloride.
Synonyms: Verpamil, Isoptin, Falicard, Phenoptin, Calan, Cardilax, Dilacoran, Falicard, Finoptin, Ikacor, Iproveratril, Isopine, Isoptin, Manidon, Vasolan, Vepamil, Verapamilhydrochlorid, Verapamil and others.
By chemical structure, the molecule of verapamil can be considered as a complicated variant of a molecule of phenylalkylamines (see Sensit).
The drug has antiadrenergic activity. Previously believed that its therapeutic effect is due to the weakening of sympathetic impulses that flow to the blood vessels, the heart and other organs. Currently, it is referred to as calcium ion antagonists, and it is one of the main drugs of this group.
Verapamil causes an expansion of the coronary vessels of the heart and increases coronary blood flow; Lowers the heart's need for oxygen. In ischemic processes in the myocardium, the drug helps to reduce the disparity between the need and supply of the heart with oxygen, both by increasing blood supply, and by better utilization and more economical consumption of the delivered oxygen.
The drug reduces myocardial contractility, but in connection with the expansion of peripheral vessels and a decrease in vascular resistance, cardiac output does not change significantly. The drug suppresses the aggregation of platelets.
Verapamil affects the conduction system of the heart, inhibits sinoatrial and atrioventricular conductivity. Has antiarrhythmic effect; Refers to antiarrhythmic drugs of the IV group (see Antiarrhythmic drugs).
In addition, it exerts some natriuretic and diuretic effects by decreasing tubular reabsorption.
In the mechanism of antianginal action of verapamil, along with antagonism with respect to calcium ions, the role of potassium ions in myocardium cells also plays a role.
Verapamil is well absorbed when taken orally. The peak concentration in the blood plasma is detected after 1 to 3 hours. However, there are significant individual differences in the pharmacokinetics of the drug. The half-life period varies from 2, 5 to 7, 5 hours after a single injection and from 4, 5 to 12 hours after repeated administration. The constant therapeutic concentration in the blood is usually achieved after 4 days from the beginning of repeated ingestion. The drug is extensively metabolized in the liver. When violations of the liver, the time of drug allocation is significantly longer. In an unchanged form, about 5% of the drug is released.
Apply verapamil inside and in the form of injections.
Inside take with chronic ischemic heart disease for the prevention of angina pectoris attacks, especially in combination with atrial extrasystole and a tendency to tachycardia.
As an antiarrhythmic agent is prescribed mainly in atrial arrhythmias: with supraventricular tachycardia, extrasystole.