Amiodarone-induced thyrotoxicosis: clinical course and predictors of outcome

J Am Coll Cardiol. 2007 Jun 19;49(24):2350-5. doi: 10.1016/j.jacc.2007.02.054. Epub 2007 Jun 4.


Objectives: This study sought to determine the clinical course and predictors of long-term outcome in patients with documented amiodarone-induced thyrotoxicosis (AIT).

Background: Amiodarone-induced thyrotoxicosis is a condition that is difficult to manage, in particular because of the long half-life of amiodarone. Data on optimal treatment for AIT are scarce.

Methods: We performed a retrospective review among patients with documented AIT at a tertiary care center. Baseline characteristics, treatment received, laboratory parameters, and events during follow-up were evaluated. The predefined composite end point consisted of the following AIT-associated complications: death, heart transplantation, hospitalization for heart failure, myocardial infarction, stroke, hospitalization for arrhythmia management, or hospitalization for treatment complications.

Results: Eighty-four patients were included in the present analysis; 27 patients received prednisone for AIT. There was no difference in time to normalization of free thyroxine between those receiving and those not receiving prednisone. Long-term follow-up showed high morbidity and mortality; 47 patients (56%) reached the primary end point. Patients receiving prednisone had a worse outcome than those not receiving prednisone (p = 0.003). Although patients received prednisone for 84 +/- 65 days, curves started to separate only 12 months after the initial diagnosis.

Conclusions: Patients with AIT have a high event rate during follow-up. Prednisone had no effect on time to normalization of thyroxine levels and was associated with an increased event rate. Importantly, AIT-related problems must be expected late, at a time when thyroid function is under control.

MeSH terms

  • Aged
  • Amiodarone / adverse effects*
  • Anti-Arrhythmia Agents / adverse effects*
  • Diagnosis, Differential
  • Female
  • Glucocorticoids / pharmacology
  • Humans
  • Hyperthyroidism / drug therapy
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Prednisone / pharmacology
  • Prognosis
  • Retrospective Studies
  • Thyroid Hormones / blood
  • Thyrotoxicosis / chemically induced*
  • Thyrotoxicosis / diagnosis
  • Thyrotoxicosis / drug therapy


  • Anti-Arrhythmia Agents
  • Glucocorticoids
  • Thyroid Hormones
  • Amiodarone
  • Prednisone