[Amiodarone and thyroid: the Janus effect].

Iodide released from Amiodarone during a chronic treatment is 100 x higher than food iodide intake. Thyroid adaptation allows normal function but over-adaptation leads to hypothyroidism and hypo-adaptation to thyrotoxicosis. Thyrotoxicosis may also result from follicular disruption. Amiodarone inhibits 5' deiodinase type I and II and hence increases serum T4 and (transiently) TSH and decreases serum T3 concentrations. Perchlorate and corticoids may be useful in the treatment of thyrotoxicosis.