[Amiodarone and thyroid: pharmacologic and toxic effects].

Amiodarone increases free T4, decreases free T3 and transiently increases TSH, that sometimes becomes undetectable. Amiodarone may induce: a) hypothyroidism, diagnosed by low free T4 and treated by l-thyroxine; b) thyrotoxicosis, diagnosed by high total or free T3, and some times requiring perchlorate, corticoids, plasmapheresis and thyroidectomy. Dysthyroidism is excluded by a normal TSH level, controlled twice a year.