Long-term outcome of thyroid function after amiodarone-induced thyrotoxicosis, as compared to subacute thyroiditis

Two main forms of amiodarone- induced thyrotoxicosis (AIT) exist: type 1 AIT is a condition of true hyperthyroidism developing in patients with pre-existing thyroid disorders, and usually requires thyroid ablative treatment. On the other hand, type 2 AIT is a form of destructive thyroiditis occurring in normal thyroids, the management of which usually consists in glucocorticoid treatment. To assess the long-term outcome of thyroid function in a prospective study of type 2 AIT patients, as compared to patients with De Quervain's subacute thyroiditis (SAT). Sixty consecutive patients with type 2 AIT were evaluated during oral glucocorticoid treatment (oral prednisone 30 mg/day, gradually tapered and withdrawn over a 3-month period) and followed for 38+/-4 months (range 6-72) thereafter. Sixty consecutive patients with SAT, referred to our Institutes during the same period and treated with the same therapeutic schedule, served as controls. Type 2 AIT patients were older (p