Drug interactions
Prochlorperazine + Thioridazine
Severity: Contraindicated
Prochlorperazine 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
Thioridazine strongly prolongs the QT interval and is linked to torsades de pointes and sudden death. Adding prochlorperazine, which also prolongs QT, further increases this risk.
What this interaction means in plain words
Prochlorperazine 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.
Prochlorperazine belongs to Central Nervous System; Thioridazine belongs to Central Nervous System.
Why it happens
Additive inhibition of cardiac repolarization, with thioridazine as a particularly potent QT-prolonging agent.
What to do
Do not combine them. Use a non-QT-prolonging alternative for nausea and review the ECG if both have been taken.
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 Prochlorperazine
- Dronedarone + Prochlorperazine Contraindicated
- Ibutilide + Prochlorperazine Contraindicated
- Nilotinib + Prochlorperazine Contraindicated
- Pimozide + Prochlorperazine Contraindicated
- Amiodarone + Prochlorperazine Major
- Amisulpride + Prochlorperazine Major
Other interactions of Thioridazine
- Abiraterone + Thioridazine Contraindicated
- Adagrasib + Thioridazine Contraindicated
- Amiodarone + Thioridazine Contraindicated
- Amisulpride + Thioridazine Contraindicated
- Amitriptyline + Thioridazine Contraindicated
- Amoxapine + Thioridazine Contraindicated
Frequently asked questions
Can I take Prochlorperazine with Thioridazine?
MediHelp rates the interaction as contraindicated. Prochlorperazine 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. Thioridazine strongly prolongs the QT interval and is linked to torsades de pointes and sudden death. Adding prochlorperazine, which also prolongs QT, further increases this risk.
How serious is the interaction between Prochlorperazine 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 combine them. Use a non-QT-prolonging alternative for nausea and review the ECG if both have been taken.
What other medicines interact with Prochlorperazine?
MediHelp also lists interactions of Prochlorperazine with, for example, Dronedarone, Ibutilide, Nilotinib. The full list is on the Prochlorperazine page.
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