Amiodarone-induced thyrotoxicosis: A review

Amiodarone-Induced Thyrotoxicosis in a Patient With Post-Ablative Hypothyroidism Controlled for 50 Years Presenting as Psychosis

“…Amiodarone is an iodine-rich class III antiarrhythmic agent that induces thyrotoxicosis in approximately 3% of patients in North America [1]. It resembles thyroxine in its molecular structure, and contains about 75 mg of iodine in each 200 mg tablet [1,2].…”

“…It resembles thyroxine in its molecular structure, and contains about 75 mg of iodine in each 200 mg tablet [1,2]. This leads to release of approximately 8 mg of free iodine into the circulation.…”

“…This leads to release of approximately 8 mg of free iodine into the circulation. The medication is very lipophilic, with a long half-life, accumulating in tissues as well as the thyroid gland [1,2]. For comparison, the recommended daily dose of iodine is 150 μg for adults over 18 years of age.…”

“…Three percent of patients treated with it develop thyroid dysfunction in the form of amiodarone-induced thyrotoxicosis (AIT) [1]. We report a case of an 85-year-old female with a remote history of radioiodine ablation of the thyroid, treated with levothyroxine along with amiodarone for chronic atrial fibrillation, who presented with weakness of 5 days and visual hallucinations of 1-month duration.…”

Vpliv amiodarona na delovanje ščitnice – Prikaz primera

“…Hkrati amiodaron vsebuje veliko količino joda, saj ta predstavlja 37 % njegove mase. Tako običajno odmerki med 100 in 600 mg na dan predstavljajo vnos 37-222 mg joda, kar je okoli 250-do 1500-krat več, kot priporoča Svetovna zdravstvena organizacija (150 mcg); vendar je potrebno upoštevati, da se le okoli 10 % z amiodaronom vnešenega joda sprosti v krvni obtok (6). Našteto lahko vodi v hiper-ali hipotirozo, povzročeno z jodom.…”