[Effects of amiodarone on the thyroid gland in euthyroid and hypothyroid animals]

Amiodarone is a benzofurane derivative which contains an appreciable amount of iodine (37%). It is used in cardiology as an antianginal and antiarrhythmic drug. Using guinea-pigs and rats as the animal model systems, the effects of amiodarone on normal and hyperplastic thyroid glands were investigated in eu- and hypothyroid animals. After the amiodarone treatment, considerable differences were observed in the levels of thyroid hormones and in the structure of the gland which proved dependent not only on the length of treatment, but also on animal species and the functional status of the gland before treatment. At extended amiodarone application, the rats with hyperplastic thyroid developed microlesions in epithelium of some follicles.