Mexiletine and Mirabegron: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Mirabegron
Mexiletine
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Increased mexiletine plasma concentrations
Interaction Deep Dive
Concurrent treatment with mexiletine, a CYP2D6 substrate1, and mirabegron, a moderate CYP2D6 inhibitor 2, may increase mexiletine plasma concentrations and the risk of adverse effects. In a small study (n=15) of patients who were either poor or extensive metabolizers of CYP2D6, concomitant administration of mexiletine with propafenone, a potent CYP2D6 inhibitor, decreased the metabolic clearance of mexiletine by approximately 70% in the extensive metabolizer group; kinetics in the poor metabolizer group were not altered 1. Appropriate monitoring is advised when mirabegron is used concomitantly with a CYP2D6 substrate 2.
Why it happens (mechanism)
Inhibition of CYP2D6-mediated mexiletine metabolism by mirabegron
Common questions
Can I take Mexiletine and Mirabegron together?
Increased mexiletine plasma concentrations Always confirm with your pharmacist or prescriber before making any change.
How serious is the Mexiletine and Mirabegron interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Mexiletine or Mirabegron need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there anything you'd monitor while I'm on both?
References (2)
- Product Information: mexiletine HCl oral capsules, mexiletine HCl oral capsules. Watson Laboratories, Inc (per DailyMed), Corona, CA, 2006. DailyMed
- Product Information: MYRBETRIQ(TM) oral extended-release tablets, mirabegron oral extended-release tablets. Astellas Pharma US, Inc. (per FDA), Northbrook, IL, 2012. DailyMed
Keep reading about Mirabegron
Keep reading about Mexiletine
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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