[Therapy of amiodarone-induced thyrotoxicosis and hypothyroidism]

Pathogenesis, diagnostic procedures and therapy of amiodarone-induced thyrotoxicosis (AIT) and hypothyroidism (AIH) are briefly discussed. Diagnosis of AIT and AIT is based on the classical signs and symptoms of thyroid dysfunction, although oligosymptomatic cases may occur, and on laboratory tests such as TSH, fT4 und fT3. In AIT, radioiodine therapy usually is no option due to the high iodine content of amiodarone. Besides withdrawal of amiodarone, medical and surgical treatment remain the only modalities. If arrhythmia can be controlled by an alternative treatment, amiodarone should be discontinued although this will not immediately restore normal thyroid function. For medical treatment, thionamides, perchlorate (not available in Switzerland), steroids (mainly for type II and mixed forms of AIT) and lithium (only for severe cases) are available. Surgery is a valid therapeutical option for severe forms of AIT which cannot be controlled adequately by medical treatment. The main advantage of surgical therapy of AIT is the rapid correction of thyrotoxicosis combined with the possibility to continue amiodarone, if it is necessary and effective. With AIH, amiodarone does not have to be stopped, if indicated and effective, and L-thyroxine is the therapy of choice.