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Drug interactions

Mexiletine + Olanzapine

Severity: Moderate

Mexiletine and Olanzapine: 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, the major pathway for olanzapine clearance, so olanzapine levels can rise. This can increase sedation, orthostatic hypotension, and anticholinergic effects.

What this interaction means in plain words

Mexiletine and Olanzapine 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; Olanzapine belongs to Central Nervous System.

Evidence level: Moderate

Why it happens

Mexiletine inhibits CYP1A2-mediated olanzapine metabolism.

What to do

Monitor for excess sedation, hypotension, and anticholinergic effects. Consider a lower olanzapine dose when starting mexiletine.

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?

Bring a full list of your medicines, including over-the-counter products, supplements and herbal remedies, to every pharmacy visit.

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Frequently asked questions

Can I take Mexiletine with Olanzapine?

MediHelp rates the interaction as moderate. Mexiletine and Olanzapine 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, the major pathway for olanzapine clearance, so olanzapine levels can rise. This can increase sedation, orthostatic hypotension, and anticholinergic effects.

How serious is the interaction between Mexiletine and Olanzapine?

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 excess sedation, hypotension, and anticholinergic effects. Consider a lower olanzapine dose when starting mexiletine.

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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