Amiodaron, repolarization inhibitor

nbsp;Amiodaron
antiarrhytmic preparation III of a class (repolarization inhibitor). Possesses also antianginalny, koronarodilatiruyushchy, alpha and beta adrenoblokiruyushchim, tireotropny and hypotensive action.
Antiarrhytmic action is caused by influence on electrophysiological processes of a myocardium; extends the potential of action of kardiomiotsit; increases the effective refractory period of auricles, ventricles, atrioventricular (AV) knot, Gis's bunch and Purkinye's fibers, additional ways of carrying out excitement. Blocking "fast" sodium channels, renders the effects characteristic of antiaritmik of the I class. Slows down slow (diastolic) depolarization of a membrane of cages of sinusovy knot, causing bradycardia and decrease in AV of conductivity.
The Antianginalny effect is caused by koronarorasshiryayushchy and antiadrenergichesky action, reduction of need of a myocardium for oxygen. Exerts the braking impact on alpha and beta adrenoblokatory cardiovascular system (without their total block). Reduces sensitivity to hyper stimulation of sympathetic nervous system, resistance of coronary vessels; increases a coronary blood-groove; urezhat heart rate; raises power reserves of a myocardium) due to increase in contents creatine of sulfate, adenosine and glycogen).
On the structure it is similar to tireoidny hormones. Content of iodine makes its about 37 molecular weights. Influences an exchange of tireoidny hormones, inhibits transformation of T3 into T4 (blockade tiroksin-5-deyodinazy) and blocks capture of these hormones of a kardiotsitama and hepatocytes that leads to weakening of the stimulating influence of tireoidny hormones on a myocardium (deficiency of E3 can lead to its hyperproduction and a thyrotoxicosis). The beginning of action (even when using "load" doses) — from 2-3 days to 2-3 months, varies duration of action from several weeks to one months (is defined in blood plasma for 9 months after the reception termination).