Dr. Ahmed Dronedarone to Amiodarone Conversion might be necessary in certain situations such as patients who develop side effects or intolerance to Dronedarone (Multaq), because of the cost, and especially if the patient is in heart failure.
It is recommended to avoid Dronedarone (Multaq) in patients with severely compromised hearts (heart failure with reduced ejection fraction – HfrEF). Such patients may need to switch from Dronedarone (Multaq) to Amiodarone.
On the other hand, if no contraindications to the use of Dronedarone (Multaq) exist and the cost is not a big issue, it may be preferred over amiodarone because of fewer side effects, and drug interactions, no effect on thyroid function, and easy dosing schedules.
Here we explain how you can switch from Dronedarone to Amiodarone or from Amioidarone to Dronedarone (Multaq).
Why you need to switch between Dronedarone and Amiodarone:
Dronedarone (or Multaq) and amiodarone are two commonly used anti-arrhythmic drugs used to treat paroxysmal atrial fibrillation and ventricular arrhythmias.
While both drugs are effective in treating arrhythmias, they have their own pros and cons necessitating the need to switch from one drug to another.
Amiodarone is a time-tested drug that has been used for several decades. It has a long half-life of about 40-60 days, which means that it can take a long time for the drug to be eliminated from the body.
This can be a disadvantage if a patient experiences side effects or needs to switch to a different medication. Amiodarone also contains iodine, which can affect the thyroid gland and lead to thyroid dysfunction.
Additionally, it has several interactions with other drugs, which can limit its use in certain patients.
On the other hand, dronedarone has a shorter half-life of about 24 hours and fewer drug interactions compared to amiodarone.
However, dronedarone is not indicated for use in patients with severe heart failure, and it may not be as effective as amiodarone in some cases.
Dronedarone to Amiodarone Conversion and Vice Versa:
There may be situations where physicians need to switch from one antiarrhythmic drug to another, either from Amiodarone to Dronedarone or from Dronedarone to Amiodarone.
When switching from one drug to another, it is important to consider the half-life of the drugs and the patient’s individual characteristics.
In general, it is recommended to wait for at least five half-lives of the drug before switching from one antiarrhythmic drug to another.
This allows the previous drug to be completely eliminated from the body and reduces the risk of adverse effects or drug interactions.
General Recommendations for Dronedarone to Amiodarone Conversion and Vice Versa:
Amiodarone to Dronedarone Conversion:
- Discontinue amiodarone and begin dronedarone after 5 half-lives (200-400mg BID)
Dronedarone to Amiodarone Conversion:
- Discontinue dronedarone and begin amiodarone after 5 half-lives (200-400mg QD or BID)
General recommendations in various heart conditions for Dronedarone to Amiodarone Conversion and Vice Versa:
Indication | Dronedarone to Amiodarone Conversion | Amiodarone to Dronedarone Conversion |
| Atrial Fibrillation | Discontinue dronedarone and wait for at least 3 to 4 half-lives before starting amiodarone | Discontinue amiodarone and wait for at least 2 to 3 weeks before starting dronedarone |
| Maintenance Therapy for Atrial Fibrillation | Start amiodarone at a low dose (200 mg daily) and titrate up to 400-600 mg daily as needed | Start dronedarone at a dose of 400 mg twice daily |
| Ventricular Arrhythmias | Start amiodarone at a dose of 800-1600 mg daily for 1-3 weeks, then titrate down to 200-400 mg daily | Start dronedarone at a dose of 400 mg twice daily |
| Heart Failure with Reduced Ejection Fraction | Dronedarone should be avoided in heart failure | Avoid switching from Amiodarone to Dronedarone. |
However, data from the ARTEMIS study has shown that a direct switch from one drug to another is safe and can reduce the chances of recurrence of atrial fibrillation.
The ARTEMIS study evaluated the safety and efficacy of directly switching from amiodarone to dronedarone or vice versa in patients with paroxysmal or persistent atrial fibrillation.
The study found that a direct switch was safe and effective, with no significant difference in recurrence rates between patients who underwent a washout period and those who underwent a direct switch.
Table summarizing the results of the ARTEMIS Trial [Ref]:
Study | Objective | Results |
| ARTEMIS AF Loading | Evaluate recurrence of AF ≤60 days after switching from amiodarone to dronedarone | Immediate switch trended towards less recurrence compared to 2-week and 4-week washout groups |
| ARTEMIS AF Long-term | Profile the pharmacokinetics of dronedarone and its metabolite according to different timings of dronedarone initiation | No significant differences in exposures among immediate, 2-week, and 4-week switch groups |
When directly switching from Amiodarone to Dronedarone or Dronedarone to Amiodarone without waiting for a washout period of five half-lives, there is an increased risk of adverse events.
In the ARTEMIS AF study, there was an increased incidence of a slow heart rate and prolongation of PR and QT intervals.
In Conclusion:
In conclusion, both dronedarone and amiodarone are effective antiarrhythmic drugs, but they have their own pros and cons.
Physicians may sometimes need to switch from one drug to another, and this can be done safely by considering the half-lives of the drugs and the patient’s individual characteristics.
While a washout period may be recommended in some cases, a direct switch can also be considered based on the results of the ARTEMIS study.
