Cordarex

Synonyms

Active substance: amiodarone

Introduction

According to Vaughan-Williams, Cordarex® belongs to the group of class – III- antiarryhtmics (potassium channel blockers) and is used for cardiac arrhythmia. The electrical action of the heart is generated in the sinus node (located at the atria) by the opening and closing of certain channels on the heart cells (heart) for the ions sodium, potassium and calcium at certain times. First, the sodium channels open and the cell depolarizes.

This is followed by an influx of calcium (plateau phase). Then a potassium outward current causes a regression of the electrical excitation (repolarisation). After complete regression, the cell can now be re-excited. During the reversion of excitation, the cells are not excitable or are more difficult to excite for some time (absolute and relative refractory phase). The active ingredient amiodarone contained in Cordarex® mainly blocks potassium channels in heart cells.

Mode of operation

The main site of action of Cordarex® are the cells in the atria, which are responsible for the formation and transmission of electrical activity. By inhibiting the potassium outward current, the regression of excitation is delayed. A new excitation can only begin later (extended refractory phase).

Besides the potassium channels, sodium and calcium channels are also blocked. This means that it also takes longer for a new excitation to develop (slower depolarisation). The result is a slower heart rate. In addition, the transmission of electrical activity (to the AV node) is reduced.

Application

Cordarex® is a very effective drug. It is used when other antiarrhythmics (medimant heart rhythm disturbances) are no longer effective or can be given. It is used to treat severe ventricular arrhythmias (ventricular dysrhythmias) and circadian rhythm disturbances. Its use is becoming increasingly important in therapy-resistant atrial flutter or atrial fibrillation. With restrictions, the drug can also be used in cases of cardiac insufficiency.

Pharmacokinetics

Cordarex is usually administered as a tablet. In some cases, however, administration by infusion may be indicated. Since it is relatively poorly soluble in water, it binds to proteins in the blood through which it is transported.

Amiodarone accumulates in the cells. For this reason, its degradation rate is very long (elimination half-life of up to 100 days). Despite the high efficacy of the active substance amiodarone, the drug should only be used if other therapy options fail because of the relatively frequent and severe side effects, especially during prolonged therapy.

The therapy starts with high doses (600 – 1000 mg per day) over eight to ten days. This is followed by the maintenance dose of 100 – 200 mg per day. After five days, a two-day break is inserted.

In acute therapy, an infusion therapy can also be initiated. Constant ECG checks are mandatory. Amiodarone (Cordarex) can interact with fats (phospholipids) and form complexes.

These are then deposited, for example, in the cornea of the eye and reduce vision. Other deposits are often found in the lungs (pulmonary fibrosis) or liver (hepatic fibrosis). Heart valves can also be affected.

The skin can react with increased sensitivity to light. Before starting and during therapy, the function of the thyroid gland must be checked thoroughly. The iodine atoms contained in Cordarex® or the active ingredient amiodarone can lead to thyroid dysfunction. Both under- and over-functions are observed. It should also be noted that all antiarrhythmic drugs can themselves trigger cardiac arrhythmia (proarrythmogenic).