Drug interactions
Darifenacin + Flecainide
Severity: Moderate
Darifenacin and Flecainide: moderate interaction.
Last updated
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
Darifenacin is a moderate CYP2D6 inhibitor, and flecainide is cleared partly by CYP2D6. Higher flecainide concentrations may increase the risk of conduction slowing and proarrhythmia, and flecainide has a narrow therapeutic window.
What this interaction means in plain words
Darifenacin and Flecainide can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Darifenacin belongs to Genitourinary; Flecainide belongs to Cardiovascular.
Why it happens
Inhibition of CYP2D6-mediated flecainide metabolism by darifenacin.
What to do
Monitor ECG (PR and QRS duration) and flecainide plasma concentrations when starting or stopping darifenacin. Reduce the flecainide dose if conduction abnormalities or toxicity appear.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Darifenacin
Other interactions of Flecainide
- Flecainide + Nirmatrelvir Contraindicated
- Flecainide + Nirmatrelvir / ritonavir Contraindicated
- Flecainide + Pimozide Contraindicated
- Flecainide + Ritonavir Contraindicated
- Flecainide + Thioridazine Contraindicated
- Flecainide + Tipranavir Contraindicated
Frequently asked questions
Can I take Darifenacin with Flecainide?
MediHelp rates the interaction as moderate. Darifenacin and Flecainide can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Darifenacin is a moderate CYP2D6 inhibitor, and flecainide is cleared partly by CYP2D6. Higher flecainide concentrations may increase the risk of conduction slowing and proarrhythmia, and flecainide has a narrow therapeutic window.
How serious is the interaction between Darifenacin and Flecainide?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor ECG (PR and QRS duration) and flecainide plasma concentrations when starting or stopping darifenacin. Reduce the flecainide dose if conduction abnormalities or toxicity appear.
What other medicines interact with Darifenacin?
MediHelp also lists interactions of Darifenacin with, for example, Atazanavir, Bethanechol, Clarithromycin. The full list is on the Darifenacin page.
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