Drug interactions
Letermovir + Propafenone
Severity: Moderate
Letermovir and Propafenone: 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
Letermovir inhibits CYP3A4 and may raise propafenone concentrations, increasing the risk of conduction disturbances and arrhythmia.
What this interaction means in plain words
Letermovir and Propafenone 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.
Letermovir belongs to Anti Virals; Propafenone belongs to Cardiovascular.
Why it happens
Inhibition of CYP3A4 by letermovir reduces propafenone metabolism.
What to do
Monitor ECG and heart rate during co-therapy, and reduce the propafenone dose if adverse effects occur.
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 Propafenone
- Dofetilide + Propafenone Contraindicated
- Dronedarone + Propafenone Contraindicated
- Nilotinib + Propafenone Contraindicated
- Nirmatrelvir / ritonavir + Propafenone Contraindicated
- Nirmatrelvir + Propafenone Contraindicated
- Pimozide + Propafenone Contraindicated
Other interactions of Letermovir
- Ergotamine + Letermovir Contraindicated
- Letermovir + Pimozide Contraindicated
- Apalutamide + Letermovir Major
- Atorvastatin + Letermovir Major
- Carbamazepine + Letermovir Major
- Colchicine + Letermovir Major
Frequently asked questions
Can I take Letermovir with Propafenone?
MediHelp rates the interaction as moderate. Letermovir and Propafenone 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. Letermovir inhibits CYP3A4 and may raise propafenone concentrations, increasing the risk of conduction disturbances and arrhythmia.
How serious is the interaction between Letermovir and Propafenone?
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 and heart rate during co-therapy, and reduce the propafenone dose if adverse effects occur.
What other medicines interact with Propafenone?
MediHelp also lists interactions of Propafenone with, for example, Dofetilide, Dronedarone, Nilotinib. The full list is on the Propafenone page.
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