Extracardiac toxic effects of amiodarone: literature review and own observations

Amiodarone (AM) is currently one of the most widely used antiarrhythmic drugs, successfully used to treat both ventricular and supraventricular arrhythmias. AM is the drug of choice in many difficult clinical situations. Despite its high efficiency and unique antiarrhythmic activity in comparison with other classes of antiarrhythmic drugs, AM has the broadest spectrum of side effects and complications – both cardiac and extracardiac. AM and its metabolites are highly lipophilic, thus accumulating in large quantities in the liver, lungs, skin, adipose tissue, the eye cornea, as well as other organs. AM-induced pulmonary toxicity is one of the most serious AM`s side effects. The development of AM-induced dysfunction of the thyroid gland, liver and other organs, in most cases, does not lead to serious consequences, but in some situations the revealed side effects are the reason for discontinuation of the drug. A number of randomized trials have emphasized that severe side effects are mainly associated with the administration of high doses of AM, and therefore its use is often limited. It is noteworthy that over the half-century history of the use of AM, indications for its administration have significantly narrowed due to its high toxicity. In recent years, there has been a tendency to prescribe low doses of AM with regular monitoring of its effectiveness and the presence of side effects. The information presented in the review can be useful for the correct use of AM in clinical practice. The article also presents our own clinical observations of severe extracardiac side effects of AM. The complications mentioned above are most often associated with excessive intake of AM, and they can be avoided or minimized by the careful adherence to the minimum maintenance dose. According to up-to-date guidelines, before prescribing any antiarrhythmic drug, it is necessary to carefully weigh not only the expected direct effect, but also take into account its possible side effects and complications.