Drug interactions
Mexiletine + Warfarin
Severity: Moderate
Mexiletine and Warfarin: 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
Mexiletine inhibits CYP1A2 and may modestly raise concentrations of the R-enantiomer of warfarin. The effect on anticoagulation is usually small but may increase INR in some patients.
What this interaction means in plain words
Mexiletine and Warfarin 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.
Mexiletine belongs to Cardiovascular; Warfarin belongs to Cardiovascular.
Why it happens
Mexiletine inhibits CYP1A2 metabolism of R-warfarin.
What to do
Check the INR more frequently after starting or stopping mexiletine. Adjust the warfarin dose to maintain the target INR.
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 Mexiletine
- Fezolinetant + Mexiletine Contraindicated
- Mexiletine + Pimozide Contraindicated
- Alosetron + Mexiletine Major
- Amiodarone + Mexiletine Major
- Clozapine + Mexiletine Major
- Cobicistat + Mexiletine Major
Other interactions of Warfarin
- Defibrotide + Warfarin Contraindicated
- Ketorolac + Warfarin Contraindicated
- Abciximab + Warfarin Major
- Acetylsalicylic acid + Warfarin Major
- Adagrasib + Warfarin Major
- Amiodarone + Warfarin Major
Frequently asked questions
Can I take Mexiletine with Warfarin?
MediHelp rates the interaction as moderate. Mexiletine and Warfarin 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. Mexiletine inhibits CYP1A2 and may modestly raise concentrations of the R-enantiomer of warfarin. The effect on anticoagulation is usually small but may increase INR in some patients.
How serious is the interaction between Mexiletine and Warfarin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Check the INR more frequently after starting or stopping mexiletine. Adjust the warfarin dose to maintain the target INR.
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.
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