Amiodarone therapy causes substantial changes in thyroid function tests and can induce thyroid dysfunction, necessitating specific guidelines for diagnosis and management.
Amiodarone is a highly eVective agent for the prophylaxis and treatment of many cardiac rhythm disturbances, ranging from paroxysmal atrial fibrillation to life threatening ventricular tachyarrhythmias. 1 Unlike many other antiarrhythmic drugs, amiodarone appears to be safe in patients with significant left ventricular dysfunction, 2-5 and may confer prognostic benefit in some patient subgroups. 6 7 Amiodarone bears a remarkable structural resemblance to thyroid hormones. The free base contains 39% iodine by weight (fig 1), and chronic treatment is associated with 40-fold increases in plasma and urinary iodide levels. 8 Amiodarone has complex eVects on thyroid physiology in all patients taking the drug, and chronic treatment is associated with substantial changes in the results of standard thyroid function tests. 0] The purposes of this review are to summarise expected and abnormal changes in thyroid function in patients taking amiodarone, and to suggest guidelines for the diagnosis and management of amiodarone induced thyroid dysfunction.
Newman et al. (Sun,) conducted a review in Amiodarone-induced thyroid dysfunction. Amiodarone was evaluated. Amiodarone therapy causes substantial changes in thyroid function tests and can induce thyroid dysfunction, necessitating specific guidelines for diagnosis and management.