Amiodarone-Induced thyroid dysfunction and ventricular tachyarrhythmias during long-term therapy in Japan.
In 232 Japanese patients receiving long-term amiodarone therapy for life-threatening ventricular tachyarrhythmias, hyperthyroidism and hypothyroidism developed in 29 patients (12.5%) and 25 patients (10.8%), respectively. In patients with hyperthyroidism, the recurrence of sustained ventricular tachycardia was significantly higher with thyrotoxicosis than in the euthyroid period (31% vs 3%, p<0.01). Holter monitoring showed that the average heart rate and ventricular premature complexes significantly increased with hyperthyroidism. On the other hand, there was no increase in the recurrence of ventricular tachyarrhythmia with hypothyroidism. There was no change in the dose or the plasma concentration of amiodarone or desethylamiodarone in the euthyroid period or when hyperthyroidism or hypothyroidism manifested. It is important to monitor for arrhythmia when hyperthyroidism develops during amiodarone therapy.
Shiga
T
T
Department of Cardiology, The Heart Institute of Japan, Tokyo Women's Medical University. mshiga@hij.twmu.ac.jp
Wakaumi
M
M
Matsuda
N
N
Shoda
M
M
Hagiwara
N
N
Sato
K
K
Kasanuki
H
H
D000328:Adult; D000368:Aged; D000638:Amiodarone / Q000008:administration & dosage / Q000009:adverse effects* / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D001145:Arrhythmias, Cardiac / Q000139:chemically induced / Q000209:etiology; D004341:Drug Evaluation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006980:Hyperthyroidism / Q000139:chemically induced / Q000150:complications / Q000503:physiopathology; D007037:Hypothyroidism / Q000139:chemically induced / Q000150:complications / Q000503:physiopathology; D007564:Japan; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D017180:Tachycardia, Ventricular / Q000150:complications / Q000188:drug therapy*; D013959:Thyroid Diseases / Q000139:chemically induced* / Q000150:complications / Q000503:physiopathology*; D018879:Ventricular Premature Complexes / Q000139:chemically induced / Q000209:etiology
C036116:desethylamiodarone; D000638:Amiodarone