PMID: 1699982Nov 1, 1990Paper

Magnitude and time course of beta-adrenergic antagonism during oral amiodarone therapy

Journal of the American College of Cardiology
A H KadishF Morady

Abstract

To examine the presence and time course of beta-adrenergic antagonism produced by amiodarone, the heart rate, QT interval and arrhythmia frequency in response to graded doses of isoproterenol were evaluated in eight patients treated with oral amiodarone for sustained ventricular tachycardia. Measurements were made before and every 2 days after beginning oral amiodarone therapy (600 mg twice daily). Isoproterenol was given in doses of 12.5, 25 and 50 ng/kg body weight per min. The mean heart rate at rest decreased from 73.1 +/- 17.8 beats/min on day 0 to 57.8 +/- 15.0 beats/min after 12 days of amiodarone therapy. A significant linear decline in heart rate at rest was observed until day 6 (p less than 0.05 for all comparisons). On all days isoproterenol produced a progressive increase in heart rate that reached 115.5 +/- 20.2 beats/min on day 0 and 94.2 +/- 18.5 beats/min on day 12. Amiodarone blunted the heart rate increase produced by isoproterenol on days 2 to 12 (p less than 0.05 versus day 0). This effect was present by day 2 and did not change significantly thereafter. The mean corrected QT (QTc) interval increased from 430 +/- 30 ms on day 0 to 449 +/- 63 ms on day 12. A significant linear increase in QTc interval was obs...Continue Reading

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Citations

Mar 1, 1994·Clinical Cardiology·J A ReiffelR DiBianco
Feb 1, 1992·Journal of the American College of Cardiology·H CalkinsF Morady
Mar 18, 2003·Current Opinion in Pediatrics·Michele R McKee
Dec 12, 1997·Journal of Cardiovascular Electrophysiology·S SicouriC Antzelevitch
Apr 23, 2004·Expert Opinion on Investigational Drugs·Sheila A Doggrell, Jules C Hancox
Nov 26, 1993·The American Journal of Cardiology·S Nattel
Nov 26, 1993·The American Journal of Cardiology·D M Roden
Sep 16, 1998·The American Journal of Cardiology·P T Sager
Nov 1, 1994·The American Journal of Cardiology·G CuiB N Singh
Jun 4, 2005·Brazilian Journal of Medical and Biological Research = Revista Brasileira De Pesquisas Médicas E Biológicas·P F OliveiraH C Salgado
Jan 4, 2008·Journal of Cardiovascular Pharmacology and Therapeutics·Sandra MoroSerge Sicouri
Jan 27, 1992·Annals of the New York Academy of Sciences·R Campbell, A Loaiza
Sep 3, 2003·Journal of Cardiovascular Electrophysiology·Hiroshi TadaFred Morady
Feb 9, 2002·American Journal of Physiology. Heart and Circulatory Physiology·Chikaya OmichiPeng-Sheng Chen
Jun 8, 2021·Curēus·Niya E SemerdzhievaChristo G Tsekov

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