Drug interactions
Pimozide + Thioridazine
Severity: Contraindicated
Pimozide and Thioridazine: 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
Both are antipsychotics with marked QT-prolonging effects. Together they greatly increase the risk of torsades de pointes and sudden death. Labeling for both drugs warns against combining them with other QT-prolonging agents.
What this interaction means in plain words
Pimozide and Thioridazine 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.
Pimozide belongs to Central Nervous System; Thioridazine belongs to Central Nervous System.
Why it happens
Additive hERG channel blockade prolonging cardiac repolarization; thioridazine may also impair pimozide clearance via CYP2D6 competition.
What to do
Do not use together; choose a single agent with lower QT risk.
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 Thioridazine
- Abiraterone + Thioridazine Contraindicated
- Adagrasib + Thioridazine Contraindicated
- Amiodarone + Thioridazine Contraindicated
- Amisulpride + Thioridazine Contraindicated
- Amitriptyline + Thioridazine Contraindicated
- Amoxapine + Thioridazine Contraindicated
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 Pimozide with Thioridazine?
MediHelp rates the interaction as contraindicated. Pimozide and Thioridazine 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. Both are antipsychotics with marked QT-prolonging effects. Together they greatly increase the risk of torsades de pointes and sudden death. Labeling for both drugs warns against combining them with other QT-prolonging agents.
How serious is the interaction between Pimozide and Thioridazine?
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 use together; choose a single agent with lower QT risk.
What other medicines interact with Thioridazine?
MediHelp also lists interactions of Thioridazine with, for example, Abiraterone, Adagrasib, Amiodarone. The full list is on the Thioridazine page.
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