Drug interactions
Mexiletine + Phenobarbital
Severity: Moderate
Mexiletine and Phenobarbital: 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
Phenobarbital is a broad enzyme inducer and can lower mexiletine concentrations, risking loss of efficacy. Additive sedation may also occur.
What this interaction means in plain words
Mexiletine and Phenobarbital 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.
Why it happens
Phenobarbital induces hepatic enzymes, increasing mexiletine clearance.
What to do
Monitor clinical response and mexiletine levels and increase the dose if needed. Reduce the dose again if phenobarbital is withdrawn.
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
Frequently asked questions
Can I take Mexiletine with Phenobarbital?
MediHelp rates the interaction as moderate. Mexiletine and Phenobarbital 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. Phenobarbital is a broad enzyme inducer and can lower mexiletine concentrations, risking loss of efficacy. Additive sedation may also occur.
How serious is the interaction between Mexiletine and Phenobarbital?
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 clinical response and mexiletine levels and increase the dose if needed. Reduce the dose again if phenobarbital is withdrawn.
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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