Drug interactions
Mexiletine + Propafenone
Severity: Major
Mexiletine and Propafenone: major interaction.
Last updated Sources: US FDA label
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
Propafenone inhibits CYP2D6 and may raise mexiletine concentrations. Both are sodium channel blocking antiarrhythmics, so the combination can produce additive conduction slowing and proarrhythmia as well as neurological and gastrointestinal toxicity.
What this interaction means in plain words
Mexiletine and Propafenone 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.
Mexiletine belongs to Cardiovascular; Propafenone belongs to Cardiovascular.
Why it happens
Propafenone inhibits CYP2D6 metabolism of mexiletine, with additive sodium channel blockade.
What to do
Use only with ECG monitoring and watch for mexiletine toxicity. Lower the mexiletine dose as needed.
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 Mexiletine and Propafenone, 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
Other interactions of Mexiletine
- Fezolinetant + Mexiletine Contraindicated
- Mexiletine + Pimozide Contraindicated
- Alosetron + Mexiletine Major
- Amiodarone + Mexiletine Major
- Clozapine + Mexiletine Major
- Cobicistat + Mexiletine Major
Other interactions of Propafenone
- Dofetilide + Propafenone Contraindicated
- Dronedarone + Propafenone Contraindicated
- Nilotinib + Propafenone Contraindicated
- Nirmatrelvir / ritonavir + Propafenone Contraindicated
- Nirmatrelvir + Propafenone Contraindicated
- Pimozide + Propafenone Contraindicated
Frequently asked questions
Can I take Mexiletine with Propafenone?
MediHelp rates the interaction as major. Mexiletine and Propafenone 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. Propafenone inhibits CYP2D6 and may raise mexiletine concentrations. Both are sodium channel blocking antiarrhythmics, so the combination can produce additive conduction slowing and proarrhythmia as well as neurological and gastrointestinal toxicity.
How serious is the interaction between Mexiletine and Propafenone?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use only with ECG monitoring and watch for mexiletine toxicity. Lower the mexiletine dose as needed.
What other medicines interact with Mexiletine?
MediHelp also lists interactions of Mexiletine with, for example, Fezolinetant, Pimozide, Alosetron. The full list is on the Mexiletine 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.
