Drug interactions
Erythromycin stearate + Pimozide
Severity: Contraindicated
Erythromycin stearate 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
Erythromycin reduces the metabolism of pimozide and raises its exposure, while both drugs prolong the QT interval. This creates a risk of serious ventricular arrhythmias including torsades de pointes.
What this interaction means in plain words
Erythromycin stearate 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
Erythromycin inhibits CYP3A4 metabolism of pimozide, with additive QT prolongation.
What to do
Do not coadminister. Select an alternative antibiotic that does not inhibit CYP3A4 or prolong QT.
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 Erythromycin stearate with Pimozide?
MediHelp rates the interaction as contraindicated. Erythromycin stearate 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. Erythromycin reduces the metabolism of pimozide and raises its exposure, while both drugs prolong the QT interval. This creates a risk of serious ventricular arrhythmias including torsades de pointes.
How serious is the interaction between Erythromycin stearate 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: Do not coadminister. Select an alternative antibiotic that does not inhibit CYP3A4 or prolong QT.
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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