Amiodarone is used to treat various cardiac arrhythmias. It is administered in tablet form and is known to work well when other antiarrhythmic drugs are unsuccessful in patients.
What is amiodarone?
Amiodarone is used to treat various cardiac arrhythmias. Amiodarone is a class III antiarrhythmic agent and is used to treat ventricular fibrillation or heart failure, among other conditions. It is administered exclusively in tablet form and is a long-term medication that remains in the body for months after treatment. Amiodarone can be used in children as well as in adults and seniors. Only during pregnancy the administration of Amiodarone is not advisable. Amiodarone treatment should not be discontinued or the dose increased without medical consultation, as this could have serious consequences on the functioning of the heart.
Pharmacologic Effect
The exact mode of action of amiodarone is not fully understood because of the complexity of the drug. It is classified as a class III antiarrhythmic drug because it strongly inhibits potassium channels and can also completely block sodium channels. In this way, and by prolonging the action potential in the heart muscle, arrhythmias are suppressed. One of the advantages of amiodarone is the fact that numerous other drugs for disorders of this type also tend to trigger arrhythmias themselves. With amiodarone, this is relatively seldom the case; moreover, these disturbances are only minor in most patients. As a rule, it is administered in tablet form with a dosage of 200 milligrams of amiodarone hydrochloride. If necessary, this dose can be reduced or increased, but this should never be done without consulting a physician. Special caution should be exercised when used in women, as the active ingredient in amiodarone remains in the body for about six months and that active ingredient can have negative effects on the development of any planned children. Pregnancy should therefore be initiated at least six months after administration of the drug.
Medical application and use
Amiodarone is used in Germany exclusively for the treatment of cardiac arrhythmias. No other uses are currently known, and off-label uses of amiodarone are also not being considered. The drug is often used to treat patients who either do not respond to other antiarrhythmic drugs or cannot use them for other reasons (side effects and interactions). It is also frequently used when beta-blockers are administered concomitantly. Specifically, amiodarone is used in ventricular fibrillation and in cardiopulmonary resuscitation. At the same time, amiodarone is considered a reliable agent in patients suffering from heart failure. In patients who have already suffered an infarction, the effect of other drugs is limited, so that amiodarone can be an effective alternative under certain circumstances. In general, amiodarone should not be used for treatment if hyperthyroidism or hypothyroidism of the thyroid gland is present, as the iodine content in amiodarone can have significant effects on the function of this organ. Interactions with other drugs, on the other hand, are hardly known. Only certain drugs that are substrates of cytochrome P450 can be expected to interact. However, studies are not yet available in this area.
Risks and side effects
Very often, deposits occur directly on the cornea of the eyes when amiodarone is administered, but this usually does not affect vision. However, increased sensitivity to light may result. Furthermore, taking amiodarone increases the risk of sunburn in light-sensitive individuals. The heart rate may decrease for weeks after treatment with amiodarone, but this very rarely results in threatening circumstances for the patient. Liver values may change slightly, but this does not necessarily represent a deterioration. Complications may also occur within the gastrointestinal tract, which are manifested by a persistent feeling of fullness as well as nausea and abdominal pain. Since amiodarone contains a proportion of iodine, it also has a direct effect on the thyroid gland. The values of the thyroid gland should be checked at regular intervals.
