Drug interactions
Grapefruit + Pimozide
Severity: Contraindicated
Grapefruit and Pimozide: contraindicated interaction.
Last updated Sources: US FDA label
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
Grapefruit juice inhibits intestinal CYP3A4 and may increase pimozide concentrations. Higher levels raise the risk of QT prolongation and ventricular arrhythmia.
What this interaction means in plain words
Grapefruit 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.
Why it happens
Inhibition of intestinal CYP3A4 reduces first-pass metabolism of pimozide.
What to do
Instruct patients to avoid grapefruit and grapefruit juice while 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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References
Other interactions of Pimozide
- Adagrasib + Pimozide Contraindicated
- Amiodarone + Pimozide Contraindicated
- Amisulpride + Pimozide Contraindicated
- Amitriptyline + Pimozide Contraindicated
- Amoxapine + Pimozide Contraindicated
- Anagrelide + Pimozide Contraindicated
Frequently asked questions
Can I take Grapefruit with Pimozide?
MediHelp rates the interaction as contraindicated. Grapefruit 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. Grapefruit juice inhibits intestinal CYP3A4 and may increase pimozide concentrations. Higher levels raise the risk of QT prolongation and ventricular arrhythmia.
How serious is the interaction between Grapefruit 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: Instruct patients to avoid grapefruit and grapefruit juice while 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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