Continuation of amiodarone therapy despite type II amiodarone-induced thyrotoxicosis.
BACKGROUND
Amiodarone is a powerful antiarrhythmic drug; however, its use may be complicated by thyrotoxicosis. When this occurs, clinicians must balance the continuation of amiodarone for antiarrhythmic purposes, and the discontinuation of treatment in order to prevent aggravation of the thyrotoxicosis. We studied the consequences of continuation or cessation of amiodarone in patients with type II amiodarone-induced thyrotoxicosis.


METHODS
Consecutive patients who developed type II amiodarone-induced thyrotoxicosis between September 1997 and September 2000 were studied. Amiodarone was continued in patients with previous ventricular arrhythmia or supraventricular arrhythmia associated with severe haemodynamic changes and was withdrawn in the other patients. In patients with persistent, severe symptomatic thyrotoxicosis, corticosteroids were added to therapy.


RESULTS
Thirteen patients were studied (nine with previous atrial fibrillation/flutter and four with ventricular tachycardia). Amiodarone treatment was continued in ten patients, including eight patients who received corticosteroids, and was temporarily halted in three patients. All patients recovered, with no difference in the duration of thyrotoxicosis between the two groups. Corticosteroid treatment was well tolerated and seemed to hasten the return to a euthyroid state (mean of 3.7 +/- 0.7 months vs 6.3 +/- 1.7 months). No recurrence of hyperthyroidism occurred during long-term follow-up.


CONCLUSIONS
In patients who require amiodarone, treatment may be safely continued despite the development of type II amiodarone-induced thyrotoxicosis.
Uzan
Laurent
L
Department of Cardiology, Cochin Hospital, Rene Descartes University, Paris, France.
Guignat
Laurence
L
Meune
Christophe
C
Mouly
Stéphane
S
Weber
Simon
S
Bertagna
Xavier
X
Bertherat
Jérôme
J
Thomopoulos
Pierre
P
Duboc
Denis
D
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000638:Amiodarone / Q000009:adverse effects* / Q000627:therapeutic use*; D000889:Anti-Arrhythmia Agents / Q000009:adverse effects* / Q000627:therapeutic use*; D016208:Databases, Factual; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017410:Practice Guidelines as Topic; D011446:Prospective Studies; D013617:Tachycardia, Supraventricular / Q000188:drug therapy*; D013971:Thyrotoxicosis / Q000139:chemically induced* / Q000175:diagnosis; D016896:Treatment Outcome; D014693:Ventricular Fibrillation / Q000188:drug therapy*
D000889:Anti-Arrhythmia Agents; D000638:Amiodarone