Amiodarone and dronedarone: The worker bee and the drone?

Abstract

Dronedarone recently has been introduced clinically as a novel drug (Multaq) for the prevention of atrial fibrillation (AF). Based largely on the ATHENA trial, the United States Food and Drug Administration (FDA) approved dronedarone for the prevention of hospitalizations due to recurrent AF, a secondary endpoint. 1 Hohnloser S.H. Crijns H.J. van Eickels M. et al. Effect of dronedarone on cardiovascular events in atrial fibrillation. N Engl J Med. 2009; 360: 668-678 Crossref PubMed Scopus (960) Google Scholar This is an unusual approval label and not normally allowed by the FDA. It also does not allow the drug to be marketed as a primary anti-AF agent. Previous studies have shown that dronedarone is marginally better than placebo in maintaining sinus rhythm in patients with a history of AF. In the EURIDIS/ADONIS trials, AF recurrence rates were high at 1 year: 75% on placebo and 64% on dronedarone. 2 Singh B.N. Connolly S.J. Crijns H.J. et al. Dronedarone for maintenance of sinus rhythm in atrial fibrillation or flutter. N Engl J Med. 2007; 357: 987-999 Crossref PubMed Scopus (599) Google Scholar However, amiodarone compared with placebo was associated with only 30% recurrence of AF in the SAFE-T trial. 3 Singh B.N. Singh S.N. Reda D.J. et al. Amiodarone versus sotalol for atrial fibrillation. N Engl J Med. 2005; 352: 1861-1872 Crossref PubMed Scopus (606) Google Scholar The DIONYSOS trial compared dronedarone directly with amiodarone. 4 Le Heuzey J.Y. De Ferrari G.M. Radzik D. Santini M. Zhu J. Davy J.M. A short-term, randomized, double-blind, parallel-group study to evaluate the efficacy and safety of dronedarone versus amiodarone in patients with persistent atrial fibrillation: the DIONYSOS study. J Cardiovasc Electrophysiol. 2010; 21: 597-605 Crossref PubMed Scopus (333) Google Scholar After cardioversion of AF and a median follow-up period of 7 months, the recurrence rates were 36.5% and 24.3% for dronedarone and amiodarone, respectively. Therefore, from a clinical standpoint it seems that amiodarone demonstrates superiority over dronedarone in AF suppression. Acute dronedarone is inferior to amiodarone in terminating and preventing atrial fibrillation in canine atriaHeart RhythmVol. 7Issue 9PreviewDronedarone is approved by the U.S. Food and Drug Administration for the treatment of patients with atrial fibrillation (AF) as a safe alternative to amiodarone. There are no full-length published reports describing the effectiveness of acute dronedarone use against AF in experimental or clinical studies. Full-Text PDF