Amiodarone-Induced Thyrotoxicosis

Amiodarone-induced thyrotoxicosis (AIT) is less common than amiodarone-induced hypothyroidism, but is more likely to pose a diagnostic and management challenge. It has been categorized into type 1 (underlying thyroid with Graves’ disease or goiter) or type 2 (normal underlying thyroid), but many cases have superimposed manifestations and can have a protracted course. AIT is associated with significant mortality and morbidity, especially in elderly patients with systolic heart failure. Refractoriness to medical therapy and cardiovascular decompensation are indications for thyroidectomy, which treats the thyrotoxicosis and also improves cardiac function. In this chapter, we discuss our approach to the diagnosis and categorization of AIT, its management, adjunct therapies, questions regarding discontinuing and resuming amiodarone, and the role of thyroidectomy in the management of AIT.