Painful autoimmune thyroiditis occurring on amiodarone therapy

A 51-year-old housewife, who had been on treatment with amiodarone for ten months, developed a painful enlargement of the thyroid gland. Thyroid antibody titers were highly elevated and a fine needle aspirate of the gland showed infiltration of lymphocytes and plasma cells. Initially the patient was hyperthyroid, later she developed hyperthyroidism which required thyroid substitution. The possibility of amiodarone provoking autoimmune thyroiditis is discussed.