title: Effects of dronedarone started rapidly after amiodarone discontinuation.
abstract: BACKGROUND
  Multiple studies have shown that amiodarone is effective in treating atrial fibrillation (AF), but is associated with a relatively high incidence of side effects; however, due to amiodarone's long elimination half-life (20-100 days), physicians may hesitate to start other drugs until it has fully cleared.
  
  
  OBJECTIVE
  A rapid switch from amiodarone to dronedarone is feasible.
  
  
  METHODS
  EURIDIS and ADONIS were double-blind, multinational, parallel-group trials comparing the efficacy and safety of dronedarone with placebo over 12 months. This retrospective subanalysis of EURIDIS/ADONIS compared the effects of dronedarone in patients discontinuing amiodarone within 2 days before randomization ("rapid switch") with results in patients who had received no amiodarone during the 2 months preceding randomization.
  
  
  RESULTS
  In total, 1237 patients were enrolled ("rapid switch", n = 154; "no amiodarone", n = 1014). In both the "rapid switch" and the "no amiodarone" groups, dronedarone users had significantly lower AF recurrence than patients receiving placebo (HR = 0.64, 95% CI, 0.44-0.95; P = 0.0224 and HR = 0.79, 95% CI, 0.67-0.92; P = 0.0027, respectively). Dronedarone users had a higher incidence of bradyarrhythmic events than placebo-treated patients. A "rapid switch" from amiodarone to dronedarone was associated with a higher incidence of serious heart failure events and heart failure hospitalizations versus all other groups. Overall event rates were low and there was no significant difference in total adverse event rates or deaths between groups.
  
  
  CONCLUSIONS
  In this patient population, a switch from amiodarone to dronedarone within a 2-day time frame might be feasible in certain patient categories, but further investigation is warranted.
authors: Department of Cardiology, Lankenau Medical Center, Wynnewood, PA, USA. laura.immordino@gmail.com
authors: Laura
authors: L
authors: Immordino
authors: Stuart
authors: S
authors: Connolly
authors: Harry
authors: H
authors: Crijns
authors: Denis
authors: D
authors: Roy
authors: Alessandro
authors: A
authors: Capucci
authors: David
authors: D
authors: Radzik
authors: Etienne
authors: E
authors: Aliot
authors: Stefan
authors: S
authors: Hohnloser
authors: Peter
authors: P
authors: Kowey
mesh_terms: D000368:Aged; D000638:Amiodarone / Q000008:administration & dosage* / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000188:drug therapy* / Q000401:mortality / Q000503:physiopathology; D001919:Bradycardia / Q000139:chemically induced; D000077764:Dronedarone; D057915:Drug Substitution; D005260:Female; D006207:Half-Life; D006333:Heart Failure / Q000139:chemically induced / Q000628:therapy; D006760:Hospitalization; D006801:Humans; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015337:Multicenter Studies as Topic; D018579:Patient Selection; D016016:Proportional Hazards Models; D016032:Randomized Controlled Trials as Topic; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome
chemical_list: D000889:Anti-Arrhythmia Agents; D000077764:Dronedarone; D000638:Amiodarone