[Clinical procedure in amiodarone-induced thyroid dysfunction]

Amiodarone is an antiarrhythmic drug frequently used in everyday clinical practice. Its mechanism of action involves the interaction with many receptors, including those in the cardiac conduction system. Amiodarone usefulness is protect in the treatment of a variety of tachyarrhythmias, both benign and life-threatening. In contrast to other antiarrhythmic drugs, amiodarone is characterized by high therapeutic efficacy, both in patients with normal and impaired left ventricular systolic function. A significant limitation of its is associated with side effects including thyroid gland dysfunction. Disturbances of this organ associated with amiodarone are an important diagnostic and therapeutic problem. They may contribute to the occurrence of both Amiodarone- Induced Thyrotoxicosis (AIT) and Amiodarone-Induced Hypothyroidism (AIH). The risk of such complications should be considered for each patient individually, taking into account thyroid function at the beginning of pharmacotherapy. Appropriate procedure, both before and after treatment allows a rapid diagnosis and treatment of thyroid disturbances. It seems that the best parameter used to assess the hormonal imbalance during amiodarone therapy is the concentration of the free triiodothyronine (fT3). The evaluation of thyroid function should be performed before starting pharmacotherapy, and then repeated every six months. In the case of a thyroid dysfunction, assessment must be performed immediately according to standard diagnostic and therapeutic regimens. Despite abnormal thyroid function, high efficiency of amiodarone and relatively small risk of thyroid damage allows continuation therapy. Amiodarone therapy requires a care from both cardiologist and endocrinologist. The aim of this paper is to present the state of art of evaluation of the thyroid function and procedures implemented in care of thyroid dysfunction before and during treatment with amiodarone.