Drug interactions
Fosaprepitant + Pimozide
Severity: Contraindicated
Fosaprepitant and Pimozide: contraindicated 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
Fosaprepitant is converted to aprepitant, which inhibits CYP3A4 and may raise pimozide levels. Pimozide has a narrow therapeutic margin for QT prolongation, so even modest increases may cause arrhythmias.
What this interaction means in plain words
Fosaprepitant and Pimozide are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two.
Fosaprepitant belongs to Gastrointestinal Tract; Pimozide belongs to Central Nervous System.
Why it happens
Aprepitant, the active metabolite, inhibits CYP3A4 and reduces pimozide clearance.
What to do
Avoid; labeling of aprepitant products lists pimozide as contraindicated. Use an antiemetic regimen without NK1 antagonists in patients on pimozide.
What to ask your pharmacist
- Is there an alternative to one of these two medicines for me?
- If both are essential, who is monitoring me and how often?
- Which symptoms mean I should stop and seek help straight away?
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Other interactions of Pimozide
- Adagrasib + Pimozide Contraindicated
- Amiodarone + Pimozide Contraindicated
- Amisulpride + Pimozide Contraindicated
- Amitriptyline + Pimozide Contraindicated
- Amoxapine + Pimozide Contraindicated
- Anagrelide + Pimozide Contraindicated
Other interactions of Fosaprepitant
- Flibanserin + Fosaprepitant Contraindicated
- Alprazolam + Fosaprepitant Moderate
- Amiodarone + Fosaprepitant Moderate
- Amobarbital + Fosaprepitant Moderate
- Apalutamide + Fosaprepitant Moderate
- Avanafil + Fosaprepitant Moderate
Frequently asked questions
Can I take Fosaprepitant with Pimozide?
MediHelp rates the interaction as contraindicated. Fosaprepitant and Pimozide are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two. Fosaprepitant is converted to aprepitant, which inhibits CYP3A4 and may raise pimozide levels. Pimozide has a narrow therapeutic margin for QT prolongation, so even modest increases may cause arrhythmias.
How serious is the interaction between Fosaprepitant and Pimozide?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid; labeling of aprepitant products lists pimozide as contraindicated. Use an antiemetic regimen without NK1 antagonists in patients on pimozide.
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.
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