Amiodarone-Induced Thyrotoxicosis Recurrence After Amiodarone Reintroduction

Abstract

Reintroduction of amiodarone in patients with a history of amiodarone-induced thyrotoxicosis (AIT) is rarely used. To date, the risk of AIT recurrence after amiodarone reintroduction is unpredicted. The aim of the study was to evaluate the risk of AIT recurrence. Retrospectively, from 2000 to 2011, all euthyroid patients with a history of AIT with amiodarone reintroduction were included. Type and severity of the first AIT, amiodarone chronology, and thyroid function evolution after reintroduction of amiodarone were investigated: 46 of 172 patients with AIT history needed amiodarone reintroduction. At first AIT episode, the mean age was 62.2 ± 16 years with male gender predominance; 65% of patients were classified as type 1 AIT. AIT recurred in 14 patients (30%), 12 patients developed hypothyroidism (26%), and 20 patients remained euthyroid (44%). Characteristics of type 1 AIT during the first episode, namely briefer exposure period to amiodarone and longer duration of treatment to normalize thyroid hormones, were predictive of AIT recurrence; 73% of patients (8 of 11) with previous episode of type 1 AIT, who did not receive a preventive thioamide treatment, developed a second episode of AIT. Thioamide preventive treatment could be useful to prevent type 1 AIT recurrence. In conclusion, AIT recurrence after amiodarone reintroduction is 4 times more frequent in patients with type 1 AIT history. Thyroid ablation before amiodarone reintroduction in patients with a history of type 1 AIT is preferred. Preventive thioamide treatment could be suggested in patients with type 1 AIT history pending for surgery.