Drug interactions
Flecainide + Ombitasvir / paritaprevir / ritonavir and dasabuvir
Severity: Major
Flecainide and Ombitasvir / paritaprevir / ritonavir and dasabuvir: 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
Ritonavir inhibits CYP enzymes including CYP2D6, which can raise flecainide concentrations. Elevated flecainide increases the risk of conduction block and ventricular proarrhythmia.
What this interaction means in plain words
Flecainide and Ombitasvir / paritaprevir / ritonavir and dasabuvir 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.
Why it happens
Ritonavir-mediated inhibition of CYP2D6 and CYP3A4 reduces flecainide metabolism.
What to do
Avoid if possible or reduce the flecainide dose, with ECG monitoring (PR, QRS) and flecainide plasma level monitoring where available.
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 Flecainide and Ombitasvir / paritaprevir / ritonavir and dasabuvir, 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 (names the partner; "Antivirals: Plasma concentrations are increased by") — 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
Frequently asked questions
Can I take Flecainide with Ombitasvir / paritaprevir / ritonavir and dasabuvir?
MediHelp rates the interaction as major. Flecainide and Ombitasvir / paritaprevir / ritonavir and dasabuvir 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. Ritonavir inhibits CYP enzymes including CYP2D6, which can raise flecainide concentrations. Elevated flecainide increases the risk of conduction block and ventricular proarrhythmia.
How serious is the interaction between Flecainide and Ombitasvir / paritaprevir / ritonavir and dasabuvir?
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 if possible or reduce the flecainide dose, with ECG monitoring (PR, QRS) and flecainide plasma level monitoring where available.
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.
