Amiodarone-induced thyrotoxicosis type 2: the role of differential diagnosis in patient management

Abstract

The antiarrhythmic drug amiodarone can affect the function of the thyroid gland, contributing to the development of thyrotoxicosis or hypothyroidism. The development of thyrotoxicosis exacerbates the cardiovascular pathology present in patients: it leads to the progression of left ventricular dysfunction, recurrence of rhythm disturbances, increasing the risk of adverse outcomes. Timely diagnosis of thyrotoxicosis in the treatment of amiodarone is of fundamental importance in choosing the right therapeutic tactics, which is determined by the type of amiodarone-induced thyrotoxicosis (AmIT), the state of the cardiovascular system, and the risk of recurrent arrhythmias. In type 1 AMIT, the main method of controlling the relief of thyrotoxicosis is thyroostatic therapy with the possibility of subsequent radical treatment (radioiodine therapy, thyroidectomy). Type 2 AmIT is a self-limiting process, however, for the treatment of patients with moderate to severe amiodarone-induced thyrotoxicosis type 2, glucocorticoids are the first-line drugs. With a mixed version of AmIT, a combination of antithyroid drugs and glucocorticoids is recommended. This review presents a clinical case of a patient with type 2 AmIT who was treated with thyrostatic drugs for a long time without achieving an effect.