Is Multaq (dronedarone) effective for treating atrial flutter?

Effectiveness of Multaq (Dronedarone) for Atrial Flutter

Dronedarone (Multaq) is recommended for patients with paroxysmal or persistent atrial flutter, but should not be used in patients with permanent atrial flutter or those with moderate to severe heart failure. 1

Mechanism and Efficacy for Atrial Flutter

Dronedarone is a multichannel blocker that inhibits sodium, potassium, and calcium channels while also possessing antiadrenergic properties. It effectively works as a rhythm-control agent for both atrial fibrillation and atrial flutter.

The ATHENA trial demonstrated that dronedarone has both rhythm and rate-controlling properties in patients with atrial fibrillation/flutter:

• Delayed time to first recurrence of atrial flutter/fibrillation (737 days vs 498 days with placebo) 2
• Reduced need for electrical cardioversion (15% vs 21% with placebo) 2
• Lower heart rates during recurrences (85.3 vs 95.5 beats/min with placebo) 2
• Reduced likelihood of progression to permanent atrial flutter/fibrillation 2

In pivotal trials, dronedarone was superior to placebo in maintaining sinus rhythm, with a median time to first AF/flutter episode of 116 days compared to 53 days with placebo 1.

Patient Selection and Contraindications

Dronedarone should be used for:

• Patients with paroxysmal or persistent atrial flutter 1
• Patients whose atrial flutter is not controlled by first-line therapy 3
• Patients with cardiovascular risk factors 3

Dronedarone should NOT be used in:

• Patients with permanent atrial flutter (Class III recommendation) 1
• Patients with NYHA Class IV heart failure 1
• Patients with decompensated heart failure within the past 4 weeks 1
• Patients with left ventricular ejection fraction <35% 1, 4

Safety Profile and Monitoring

Dronedarone has a more favorable safety profile compared to amiodarone:

• Fewer thyroid, neurological, skin, and ocular adverse events 1
• No iodine moiety, reducing thyroid toxicity 4
• Less lipophilic with shorter half-life than amiodarone 4

However, important safety considerations include:

• Gastrointestinal side effects (nausea, vomiting, diarrhea) are common 5
• Rare cases of severe hepatotoxicity have been reported 1
• Monitor liver function tests during long-term treatment 1
• Avoid concomitant use with dabigatran (P-glycoprotein interaction) 1
• Avoid concomitant use with digoxin due to potential increased mortality risk 1

Comparison with Other Antiarrhythmics

While dronedarone is effective for atrial flutter, it is less effective than amiodarone:

• Amiodarone is more effective in maintaining sinus rhythm than dronedarone 1, 3
• However, amiodarone has more significant toxicity concerns 6

Treatment Algorithm for Atrial Flutter

1. First-line therapy: Beta-blockers or calcium channel blockers for rate control
2. For rhythm control in patients with paroxysmal/persistent atrial flutter:
   • If first-line therapy fails and patient has cardiovascular risk factors, consider dronedarone
   • If patient has structural heart disease but no advanced heart failure, dronedarone is appropriate
   • If patient has severe heart failure, amiodarone should be used instead of dronedarone
3. Monitor:
   • Effectiveness in maintaining sinus rhythm
   • Heart rate during any recurrences
   • Liver function tests periodically
   • Signs of heart failure

Conclusion

Dronedarone is an effective option for treating atrial flutter in appropriately selected patients, particularly those with paroxysmal or persistent atrial flutter who have failed first-line therapy. Its efficacy in preventing recurrences and controlling ventricular rate during recurrences makes it a valuable treatment option, though it should be avoided in patients with permanent atrial flutter or moderate to severe heart failure.