Drug interactions
Darifenacin + Mexiletine
Severity: Moderate
Darifenacin and Mexiletine: 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 is metabolised partly by CYP2D6, which darifenacin inhibits, so mexiletine levels may rise. Because mexiletine has a narrow therapeutic index, this could increase neurological and cardiac toxicity.
What this interaction means in plain words
Darifenacin and Mexiletine 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.
Darifenacin belongs to Genitourinary; Mexiletine belongs to Cardiovascular.
Why it happens
Inhibition of CYP2D6 by darifenacin reduces mexiletine clearance.
What to do
Monitor for tremor, dizziness, nausea and arrhythmia, and check mexiletine levels if available. Reduce the mexiletine dose if 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 Darifenacin
Other interactions of Mexiletine
- Fezolinetant + Mexiletine Contraindicated
- Mexiletine + Pimozide Contraindicated
- Alosetron + Mexiletine Major
- Amiodarone + Mexiletine Major
- Clozapine + Mexiletine Major
- Cobicistat + Mexiletine Major
Frequently asked questions
Can I take Darifenacin with Mexiletine?
MediHelp rates the interaction as moderate. Darifenacin and Mexiletine 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 is metabolised partly by CYP2D6, which darifenacin inhibits, so mexiletine levels may rise. Because mexiletine has a narrow therapeutic index, this could increase neurological and cardiac toxicity.
How serious is the interaction between Darifenacin and Mexiletine?
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 for tremor, dizziness, nausea and arrhythmia, and check mexiletine levels if available. Reduce the mexiletine dose if toxicity appears.
What other medicines interact with Darifenacin?
MediHelp also lists interactions of Darifenacin with, for example, Atazanavir, Bethanechol, Clarithromycin. The full list is on the Darifenacin page.
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