Clinical electrophysiologic effects of a single high oral dose of amiodarone.
Several recent reports have described the antiarrhythmic effects of a single high oral dose of amiodarone but clinical electrophysiologic effects have not been reported. The present study was performed to assess electrophysiologic effects in 12 patients. After baseline electrophysiologic studies (EPS) patients were administered a single oral dose of 30 mg/kg of amiodarone. EPS was repeated 7.5 +/- 0.5 hours later. Plasma levels of amiodarone and its metabolite desethylamiodarone were determined at the time of the second EPS, Holter monitoring was performed for 24 hours after amiodarone administration. Amiodarone significantly increased the following parameters: corrected QT interval (+4.5%), functional refractory period of the right atrium (+7%); AH interval (+12.3%), effective refractory period of the atrioventricular node (+18.5%), and cycle length of Wenckebach block (+8.4%). These effects were not correlated with plasma levels of amiodarone and desethylamiodarone. Holter monitoring detected no significant bradycardia or arrhythmia. These findings indicate that the effects of a single high oral dose of amiodarone are the same as those known to be induced by acute intravenous administration.
Deharo
J C
JC
Cardiology department, Hôpital Sainte Marguerite, CHU Marseille, France.
Durand
A
A
Macaluso
G
G
Malaterre
H
H
Le Tallec
L
L
Panagides
D
D
Bory
M
M
Djiane
P
P
D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000638:Amiodarone / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000097:blood / Q000494:pharmacology* / Q000627:therapeutic use; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology* / Q000627:therapeutic use; D001145:Arrhythmias, Cardiac / Q000188:drug therapy / Q000503:physiopathology; D001283:Atrioventricular Node / Q000187:drug effects / Q000503:physiopathology; D002036:Bundle of His / Q000187:drug effects / Q000503:physiopathology; D004562:Electrocardiography; D004594:Electrophysiology; D005260:Female; D006325:Heart Atria / Q000187:drug effects / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011690:Purkinje Fibers / Q000187:drug effects / Q000503:physiopathology; D012849:Sinoatrial Node / Q000187:drug effects / Q000503:physiopathology; D016278:Ventricular Function, Right / Q000187:drug effects
D000889:Anti-Arrhythmia Agents; C036116:desethylamiodarone; D000638:Amiodarone