[Amiodarone and thyroid function]

Amiodarone is a drug which is frequently used in cardiology, and which can lead to the appearance of hyper- of hypo-thyroidism in certain cases. A study of the various parameters of thyroid function has shown that these are abnormal in every case treated by this drug, without the biochemical abnormalities necessarily being reflected clinically. The authors outline a method which will allow a distinction to be drawn between patients with a true thyroid malfunction and those whose biochemical results do not appear at first sight to be of any consequence. Regular assays of the T3RIA level are suggested as a means of early detection of thyroid malfunction in patients undergoing treatment with amiodarone.