Antiadrenergic cardiovascular adverse effects of high-dose amiodarone loading regimen.
A 55-year-old patient with inferior wall infarction was treated effectively for ventricular tachycardia with high-dose oral amiodarone loading regimen (5 g within 16 hours). Serial pharmacokinetic studies demonstrated a rapid temporary increase in amiodarone plasma concentration to a maximum of 3.40 micrograms/ml 17 hours after initiation of therapy followed by a return to normal plasma concentration within 8 hours. During fast drug evasion the patient developed acute low-output syndrome with syncope successfully controlled with intravenous catecholamine administration. Our findings suggest that the cardiovascular collapse was caused by the non-competitive adrenoceptor antagonism of amiodarone resulting in secondary autonomic insufficiency.
Steurer
G
G
Department of Cardiology, University of Vienna, Austria.
Schmidinger
H
H
Frey
B
B
D000284:Administration, Oral; D000638:Amiodarone / Q000008:administration & dosage / Q000009:adverse effects* / Q000493:pharmacokinetics; D002303:Cardiac Output, Low / Q000139:chemically induced*; D002395:Catecholamines / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications; D011941:Receptors, Adrenergic / Q000187:drug effects; D013575:Syncope / Q000209:etiology; D013610:Tachycardia / Q000188:drug therapy
D002395:Catecholamines; D011941:Receptors, Adrenergic; D000638:Amiodarone