Medication Description: Amiodarone (Amiodaronum)
AMYODARON (Amiodaronum) *. [2-Butyl-3-benzofuranyl] - [4- (2-diethyl-aminoethoxy) -3, 5-diiodophenyl] ketone hydrochloride.
Synonyms: Cordaron, Palpitin, Amjodaronum, Angoron, Atlansil, Сordaron, Сordinil, Рalpitin, Sedacoron, Trangorex, etc.
Amiodarone is the main representative of antiarrhythmic drugs of group III.
Initially, amiodarone was proposed as a coronary-expanding (antianginal) agent for the treatment of chronic forms of coronary artery disease. In the future, its antiarrhythmic properties were identified and now it is widely used as a highly effective antiarrhythmic drug. However, as an antianginal agent, amiodarone has not lost its value.
The antianginal effect of amiodarone is due in part to its antispasmodic (vasodilator) and antiadrenergic action. It has an inhibitory effect on the a and b -adrenoreceptors of the cardiovascular system, without causing their complete blockade. However, it increases the tone of the sympathetic nervous system. The drug reduces the resistance of the coronary vessels of the heart and increases coronary blood flow, slows heart contractions, reduces myocardial oxygen demand, increases the myocardial energy reserves (increases the creatinine sulfate, adenosine and glycogen levels). It somewhat reduces peripheral vascular resistance and systemic blood pressure.
Unlike drugs that completely block b -adrenoreceptors, amiodarone has almost no negative inotropic effects.
As well as a number of other antianginal drugs, possessing to some degree antiadrenergic activity, amiodarone reduces the sensitivity to the hyperstimulation of the sympathetic nervous system.
The drug has a pronounced effect on the electrophysiological processes of the myocardium. It significantly lengthens the action potential of cardiomyocytes and thus increases the effective refractory period of the atria, ventricles, atrioventricular node, His bundle and Purkinje fibers, as well as additional ways of conducting excitation. It can also inhibit the slow (diastolic) depolarization of the cell membrane of the sinus node and other cardiomyocytes and directly affect the automaticity of the heart. These and other properties of amiodarone, which determine its high efficacy in various types of arrhythmias, have given reason to distinguish it as a special (III) group of antiarrhythmic drugs.
Amiodarone is slowly absorbed when ingested. It is detected in the blood in 1/2 - 4 hours. The maximum concentration in the blood is observed in 5 - 6 hours.
Excreted from the body extremely slowly, the half-life is 30 days or more. With continuous use, the drug accumulates in the body (cumulation).
The therapeutic effect usually occurs within a few days from the beginning of the reception and reaches a maximum after 2 to 4 weeks. At higher doses, the effect may come faster.