Drug interactions
Dronedarone + Flecainide
Severity: Major
Dronedarone and Flecainide: major interaction.
Last updated Sources: UK SmPC
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Dronedarone inhibits CYP2D6 and may raise flecainide levels, while both drugs affect cardiac conduction and repolarization. The combination increases the risk of bradycardia, conduction block, and ventricular arrhythmia, and flecainide is unsafe in structural heart disease.
What this interaction means in plain words
Dronedarone and Flecainide can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Dronedarone belongs to Cardiovascular; Flecainide belongs to Cardiovascular.
Why it happens
Dronedarone inhibits CYP2D6 metabolism of flecainide, with additive QT and conduction effects.
What to do
Avoid the combination where possible. If used, monitor ECG closely and reduce the flecainide dose, checking plasma levels.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Dronedarone and Flecainide, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
References
- Flecainide Acetate 100 mg tablets - SmPC sections 4.3/4.5 (class statement: Class III antiarrhythmics; "Class III antiarrhythmics: If flecainide is given in the presence of") — electronic medicines compendium (UK SmPC)
Other interactions of Flecainide
- Flecainide + Nirmatrelvir Contraindicated
- Flecainide + Nirmatrelvir / ritonavir Contraindicated
- Flecainide + Pimozide Contraindicated
- Flecainide + Ritonavir Contraindicated
- Flecainide + Thioridazine Contraindicated
- Flecainide + Tipranavir Contraindicated
Other interactions of Dronedarone
- Adagrasib + Dronedarone Contraindicated
- Amiodarone + Dronedarone Contraindicated
- Arsenic trioxide + Dronedarone Contraindicated
- Artemether / lumefantrine + Dronedarone Contraindicated
- Atazanavir + Dronedarone Contraindicated
- Azithromycin + Dronedarone Contraindicated
Frequently asked questions
Can I take Dronedarone with Flecainide?
MediHelp rates the interaction as major. Dronedarone and Flecainide can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Dronedarone inhibits CYP2D6 and may raise flecainide levels, while both drugs affect cardiac conduction and repolarization. The combination increases the risk of bradycardia, conduction block, and ventricular arrhythmia, and flecainide is unsafe in structural heart disease.
How serious is the interaction between Dronedarone and Flecainide?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination where possible. If used, monitor ECG closely and reduce the flecainide dose, checking plasma levels.
What other medicines interact with Flecainide?
MediHelp also lists interactions of Flecainide with, for example, Nirmatrelvir, Nirmatrelvir / ritonavir, Pimozide. The full list is on the Flecainide page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
