Drug interactions
Duloxetine + Flecainide
Severity: Moderate
Duloxetine 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
Duloxetine is a moderate CYP2D6 inhibitor and flecainide is mainly cleared by CYP2D6. Flecainide exposure may rise, increasing the risk of conduction slowing and proarrhythmia, particularly in patients with structural heart disease or renal impairment.
What this interaction means in plain words
Duloxetine 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.
Duloxetine belongs to Central Nervous System; Flecainide belongs to Cardiovascular.
Why it happens
Inhibition of CYP2D6-mediated flecainide metabolism by duloxetine.
What to do
Monitor ECG (PR and QRS duration) and flecainide plasma concentrations when starting or stopping duloxetine. Reduce the flecainide dose if conduction intervals lengthen or toxicity appears.
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 Flecainide
- Flecainide + Nirmatrelvir Contraindicated
- Flecainide + Nirmatrelvir / ritonavir Contraindicated
- Flecainide + Pimozide Contraindicated
- Flecainide + Ritonavir Contraindicated
- Flecainide + Thioridazine Contraindicated
- Flecainide + Tipranavir Contraindicated
Other interactions of Duloxetine
- Duloxetine + Isocarboxazid Contraindicated
- Duloxetine + Linezolid Contraindicated
- Duloxetine + Methylene blue Contraindicated
- Duloxetine + Phenelzine Contraindicated
- Duloxetine + Procarbazine Contraindicated
- Duloxetine + Rasagiline Contraindicated
Frequently asked questions
Can I take Duloxetine with Flecainide?
MediHelp rates the interaction as moderate. Duloxetine 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. Duloxetine is a moderate CYP2D6 inhibitor and flecainide is mainly cleared by CYP2D6. Flecainide exposure may rise, increasing the risk of conduction slowing and proarrhythmia, particularly in patients with structural heart disease or renal impairment.
How serious is the interaction between Duloxetine 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 duloxetine. Reduce the flecainide dose if conduction intervals lengthen or toxicity appears.
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.
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