Relation between amiodarone and desethylamiodarone plasma concentrations and electrophysiologic effects, efficacy and toxicity

Because the value of monitoring amiodarone plasma concentrations remains undefined, this study was performed to evaluate its role during the management of patients receiving amiodarone. The early electrophysiologic effects of amiodarone were assessed in 40 consecutive patients with coronary artery disease and sustained ventricular tachycardia or fibrillation who underwent electrophysiologic studies and measurement of amiodarone plasma concentration before and 29 +/- 15 (mean +/- SD) days after initiation of therapy. Amiodarone and desethylamiodarone plasma levels did not correlate with changes in either sinus cycle length, QTc interval, ventricular effective refractory period, AH and HV intervals or ventricular tachycardia cycle length. Amiodarone and desethylamiodarone plasma concentrations and the effects of the drug on conduction intervals or right ventricular effective refractory periods were not related to suppression of arrhythmia induction by ventricular stimulation after 1 month of therapy. The relation between amiodarone plasma concentrations and both toxicity and efficacy during long-term therapy were prospectively assessed in a larger series of 114 consecutive patients with either symptomatic supraventricular or ventricular arrhythmias who were followed up on long-term amiodarone therapy for 26 +/- 15 months. Sixty-three patients (55%) had one or more adverse effects attributed to amiodarone. By life-table analysis, 40, 69 and 80% of patients had experienced an adverse reaction after 1, 2 and 3 years of therapy, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

This article has been cited by other articles:

				S. Ahmed, M. Rienstra, H. J. G. M. Crijns, T. P. Links, A. C. P. Wiesfeld, H. L. Hillege, H. A. Bosker, D. J. A. Lok, D. J. Van Veldhuisen, I. C. Van Gelder, et al. Continuous vs Episodic Prophylactic Treatment With Amiodarone for the Prevention of Atrial Fibrillation: A Randomized Trial JAMA, October 15, 2008; 300(15): 1784 - 1792. [Abstract] [Full Text] [PDF]

				S. Le Bouter, A. El Harchi, C. Marionneau, C. Bellocq, A. Chambellan, T. van Veen, C. Boixel, B. Gavillet, H. Abriel, K. Le Quang, et al. Long-Term Amiodarone Administration Remodels Expression of Ion Channel Transcripts in the Mouse Heart Circulation, November 9, 2004; 110(19): 3028 - 3035. [Abstract] [Full Text] [PDF]

				J. Merot, F. Charpentier, J.-M. Poirier, G. Coutris, and J. Weissenburger Effects of chronic treatment by amiodarone on transmural heterogeneity of canine ventricular repolarization in vivo: interactions with acute sotalol Cardiovasc Res, November 1, 1999; 44(2): 303 - 314. [Abstract] [Full Text] [PDF]

				E. Drouin, G. Lande, and F. Charpentier Amiodarone reduces transmural heterogeneity of repolarization in the human heart J. Am. Coll. Cardiol., October 1, 1998; 32(4): 1063 - 1067. [Abstract] [Full Text] [PDF]