胺碘酮很可能延迟诱发甲状腺毒症

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胺碘酮很可能延迟诱发甲状腺毒症
Amiodarone-Induced Thyrotoxicosis Likely to Be Delayed

NEW YORK (Reuters Health) Jun 21 - Adverse effects associated with amiodarone-induced thyrotoxicosis are likely to appear during late follow-up, even after thyroid function is under control, perhaps many months after initial onset, Swiss researchers report in the June 19th issue of the Journal of the American College of Cardiology.

Dr. Stefan Osswald and colleagues at University Hospital Basel note that amiodarone is an effective drug for maintaining sinus rhythm in patients with atrial fibrillation and it reduces shock delivery in those with implanted defibrillators.

It has other advantages, but can be associated with significant side effects, among them, thyroid dysfunction. To gain further information on the course of the disorder, the researchers retrospectively studied 84 patients with amiodarone-induced thyrotoxicosis.

Of these, 27 (32%) had received prednisolone. This had no effect on the time to normalization of free thyroxine. Nevertheless, there was high morbidity and mortality, with the prednisolone group doing significantly worse.

However, this did not become apparent until 12 months after the initial diagnosis in patients who had had prednisolone treatment for a mean of almost 3 months. Some 41% these patients required hospitalization for arrhythmia management compared to 21% of patients who did not receive the steroid.

At follow-up of 50 months, 47 patients (56%) had reached a composite end point including death, heart transplantation, hospitalization for heart failure, arrhythmia, myocardial infarction and stroke. Those with abnormal left ventricular function were at higher risk.

\"The high event rate suggests the need for close monitoring,\" the researchers point out, and those who may benefit from prednisolone therapy should be carefully selected.

The team recommends \"prolonged follow-up visits after normalization of thyroid function.\" In particular, they conclude, \"clinicians should look for overt or silent arrhythmia recurrence, the most common complication during long-term follow-up.

Am J 2007;49:2350-2355.