[Amiodarone-induced hyperthyroidism].
Amiodarone is extensively used in cardiology practice because of its excellent antiarrhythmic properties. It produces alterations in thyroid functional because it contains 37% iodine and it is structurally similar to the thyroid hormones. Amiodarone inhibits 5'-deiodinase in the liver. The incidence of amiodarone-induced hyperthyroidism is between 6% and 12% of treated patients. The figures for pediatric patients are similar. Determination of tri-iodothyronine (T3), thyroxine (T4) and thyroid-stimulating hormone (TSH) plays an important role in the diagnosis and follow-up of thyroid alterations. Treatment options in amiodarone-induced hyperthyroidism in children include thionamide, potassium perchlorate, and prednisone. We present the case of hyperthyroidism secondary to amiodarone in a 10-year-old boy with Marfan's syndrome who was admitted several times for crises of paroxysmal supraventricular tachycardia and atrial fibrillation. After amiodarone treatment he presented a clinical and analytical picture of hyperthyroidism with very low TSH levels and increased free-T4 levels. Thyroid echography and scintigraphy were normal. Treatment with thiamazole did not alter the clinical picture, which returned to normal after prednisone administration. Currently, prednisone is being slowly withdrawn.Amiodarone. Hyperthyroidism. Antiarrhythmics.
Pérez Parras
M A
MA
Servicio de Pediatría. Hospital General de Especialidades Ciudad de Jaén. amnegrillo@colmedjaen.org
Marín Patón
M
M
Negrillo Cantero
A M
AM
Caro Cruz
E
E
González Rivera
F
F
Moreno Carazo
A
A
D000638:Amiodarone / Q000009:adverse effects*; D000889:Anti-Arrhythmia Agents / Q000009:adverse effects*; D002648:Child; D006801:Humans; D006980:Hyperthyroidism / Q000139:chemically induced*; D008297:Male; D008382:Marfan Syndrome / Q000150:complications; D013614:Tachycardia, Paroxysmal / Q000188:drug therapy
D000889:Anti-Arrhythmia Agents; D000638:Amiodarone