Amiodarone-induced thyrotoxicosis

Amiodarone is the most important drug in the treatment of ventricular arrhy thmias and is widely used for atrial fibrillation. Thyrotoxicosis, a classi cal side effect, was thought to be iodine induced, but recent evidence sugg ests that other mechanisms play an important role (toxic effect on thyreocy tes, immunological effects). Thyrotoxicosis due to amiodarone is difficult to treat and is further complicated by the pro-arrhythmic potential of thyr otoxicosis and the fading antiarrhythmic effect after amiodarone withdrawal . The mechanism, diagnosis and therapy of amiodarone-induced thyrotoxicosis a re discussed in the light of the available literature.