Severe amiodaron: induced thyrotoxicosis
A. Dokupilova1 & J. Payer2
Indroduction: Amiodaron is an potent antiarrhythmic drug used for the treatment of ventricular and supraventricular arrhythmias. Long-term amiodaron therapy can cause a thyroid abnormalities in up to 1418% patients. There are two main forms of AIT: type 1, a form of iodine-induced hyperthyroidism, and type 2, a drug-induced destructive thyroiditis. Differentiation of these 2 types is essential for determining the best management of the disease.
Case report: We present a case of severe amiodaron-induced thyrotoxicosis. 68 years old man with heart failure and severe systolic dysfunction EF 25%, after implantation of ICD in secondary prevention of sudden cardiac arrest was admitted to our cardiology department after 3 electrical shocks. Patient has been using amiodaron for at least 2 years. We have established the correct function of ICD. Patient had the following laboratory findings: uTSH 0.005 (0.34.2 μIU/l), fT4 > 100 (1222 pmol/l), fT3 18.2 (3.16.8 pmol/l), antiTPO 12 (060 IU/l), antiTG 18 (060 IU/l), TRAK 0.1 (01 IU/l). The clinical presentation has included fatigue, weight loss and profound muscle weakness. Color flow Doppler sonography has shown absent hypervascularity, there were a thyroid nodule 10 mm in diameter. There was no improvement in laboratory finding and clinical asessement after discontinuation of amiodaron therapy for more than 2 months. We started a treatment with thionamides in daily dose 60 mg. No effect of these therapy was recorded, so we have to use a combined treatment with thionamides 60 mg daily dose, corticosteroids in daily dose 60 mg and potassium perchlorate in daily dose 800 mg. Improvement has shown 1 week following the start of therapy. Patient has became euthyroid after 23 month of the therapy.
Conclusion: Amiodaron is often used in cardiology for the treatment of severe ventricular and supraventricular arrhythmias. In some cases can cause a thyroid dysfunction. Recognition of AIT form is useful for the best treatment of disease.
Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.