Acute treatment of recent-onset atrial fibrillation and flutter with a tailored dosing regimen of intravenous amiodarone

Abstract

A 24 h intravenous dosing regimen of amiodarone was designed to reach a peak plasma concentration at 1 h and to maintain the concentration above a certain level during the infusion period. A randomized, open-label, digoxin-controlled study was undertaken to observe the efficacy and safety of the dosing regimen of amiodarone in treating recent-onset, persistent, atrial fibrillation and flutter with ventricular rates above 130 beats.min-1. Fifty patients with a mean age of 70 +/- 7 (SD) years were enrolled and randomly assigned to receive either amiodarone intravenously (n = 26) or digoxin (n = 24). Amiodarone HCl was infused over 24 h according to the following regimen: 5 mg.min-1, 3 mg.min-1, 1 mg.min-1 and 0.5 mg.min-1 for 1, 3, 6 and 14 h, respectively, for a 70-kg subject. Digoxin (0.013 mg.kg-1) was infused in three divided doses, each dose 2 h apart and infused over 30 min. The mean heart rates in the amiodarone group decreased significantly from 157 +/- 20 beats.min-1 to 122 +/- 25 beats.min-1 after 1 h (P < 0.05 vs baseline), and then decreased further to stabilize at 96 +/- 25 beats.min-1 after 6 h (P < 0.05). The digoxin group had fewer dramatic alterations in heart rates, compared to the amiodarone group, in the first 8 h (P < 0.05, respectively). Maximum reduction was reached only after 8 h. The amiodarone infusion was prematurely aborted in two patients due to severe bradycardia and death after conversion in one patient and aggravation of heart failure in the other.(ABSTRACT TRUNCATED AT 250 WORDS)

Efficacy, Safety, and Determinants of Conversion of Atrial Fibrillation and Flutter With Oral Amiodarone

“…Because plasma levels of desethylamiodarone only increase gradually with prolonged therapy, reaching approximately 80% of that of amiodarone in several months, 26,27 conversion is expected to occur later, whereas effects on rate control will occur early after instituting ther-apy. 28,29 Whether prolonged oral amiodarone loading is also accompanied by an increase in the number of patients who undergo conversion remains to be established.…”

2016 ESC Guidelines for the management of atrial fibrillation developed in collaboration with EACTS

“…U pacjentów z HFrEF należy stosować beta-adrenolityki, preparaty naparstnicy (digoksynę lub digitoksynę) bądź ich skojarzenia [218,533], ponieważ diltiazem i werapamil mogą wywierać ujemne działanie inotropowe u pacjentów z LVEF < 40% [222,534,535]. U pacjentów w krytycznie ciężkim stanie oraz tych ze znacznie zaburzoną czynnością skurczową lewej komory można stosować amiodaron dożylnie, jeżeli zbyt szybka czynność komór prowadzi do niestabilności hemodynamicznej [536][537][538]. U pacjentów w niestabilnym stanie klinicznym należy rozważyć pilną kardiowersję (patrz rozdz.…”

Intravenous amiodarone for cardioversion of recent‐onset atrial fibrillation

“…The results of these studies are discordant: the efficacy rate varies from only 59% to as much as 92%. The remaining published studies [11][12][13][14][15][16] dealt either with patients with longer AF duration or oral loading of amiodarone.…”