Drug interactions
Mexiletine + Quinidine
Severity: Moderate
Mexiletine and Quinidine: 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
Quinidine can raise mexiletine levels through CYP2D6 inhibition, increasing the risk of neurological toxicity such as tremor, dizziness and ataxia, and of proarrhythmia. The two drugs are also sometimes combined deliberately for additive antiarrhythmic effect.
What this interaction means in plain words
Mexiletine and Quinidine 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; Quinidine belongs to Anti Parasitic.
Why it happens
CYP2D6 inhibition by quinidine reduces mexiletine metabolism.
What to do
Monitor for mexiletine toxicity and ECG changes, and lower the mexiletine dose if needed.
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 Quinidine
- Adagrasib + Quinidine Contraindicated
- Arsenic trioxide + Quinidine Contraindicated
- Artemether / lumefantrine + Quinidine Contraindicated
- Chloroquine + Quinidine Contraindicated
- Dofetilide + Quinidine Contraindicated
- Dronedarone + Quinidine Contraindicated
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 Quinidine?
MediHelp rates the interaction as moderate. Mexiletine and Quinidine 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. Quinidine can raise mexiletine levels through CYP2D6 inhibition, increasing the risk of neurological toxicity such as tremor, dizziness and ataxia, and of proarrhythmia. The two drugs are also sometimes combined deliberately for additive antiarrhythmic effect.
How serious is the interaction between Mexiletine and Quinidine?
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 mexiletine toxicity and ECG changes, and lower the mexiletine dose if needed.
What other medicines interact with Quinidine?
MediHelp also lists interactions of Quinidine with, for example, Adagrasib, Arsenic trioxide, Artemether / lumefantrine. The full list is on the Quinidine page.
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