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Drug interactions

Pimozide + Tucatinib

Severity: Major

Pimozide and Tucatinib: major 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

Tucatinib inhibits CYP3A4 and can increase pimozide exposure. Higher pimozide levels increase the risk of QT prolongation and torsades de pointes.

What this interaction means in plain words

Pimozide and Tucatinib can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.

Pimozide belongs to Central Nervous System; Tucatinib belongs to Oncology.

Evidence level: Moderate

Why it happens

Inhibition of CYP3A4-mediated pimozide metabolism by tucatinib.

What to do

Avoid the combination and select an alternative to pimozide. If unavoidable, reduce the pimozide dose and monitor ECG.

What to ask your pharmacist

  • Does the benefit of taking both outweigh the risk in my case?
  • Do I need any blood test, ECG or other check while on both?
  • What early warning signs should I watch for, and what should I do if they appear?

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 Pimozide with Tucatinib?

MediHelp rates the interaction as major. Pimozide and Tucatinib can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Tucatinib inhibits CYP3A4 and can increase pimozide exposure. Higher pimozide levels increase the risk of QT prolongation and torsades de pointes.

How serious is the interaction between Pimozide and Tucatinib?

MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination and select an alternative to pimozide. If unavoidable, reduce the pimozide dose and monitor ECG.

What other medicines interact with Pimozide?

MediHelp also lists interactions of Pimozide with, for example, Adagrasib, Amiodarone, Amisulpride. The full list is on the Pimozide page.

Full monographs, dosing and an interaction checker in the MediHelp app

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