Drug interactions
Etrasimod + Thioridazine
Severity: Major
Etrasimod and Thioridazine: major interaction.
Last updated Sources: EMA SmPC
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
Etrasimod can slow heart rate and delay AV conduction when started. Combined with thioridazine, a strongly QT-prolonging drug, the risk of torsades de pointes is higher, particularly with bradycardia.
What this interaction means in plain words
Etrasimod and Thioridazine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Etrasimod belongs to Gastrointestinal Tract; Thioridazine belongs to Central Nervous System.
Why it happens
Additive QT prolongation, with etrasimod-induced bradycardia increasing proarrhythmic susceptibility.
What to do
Avoid the combination where possible and choose a less QT-active antipsychotic. If it is essential, obtain a baseline ECG, monitor it after initiation and correct potassium and magnesium.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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References
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 Etrasimod
- Abatacept + Etrasimod Major
- Amiodarone + Etrasimod Major
- Anagrelide + Etrasimod Major
- Anakinra + Etrasimod Major
- Anti-thymocyte + Etrasimod Major
- Asenapine + Etrasimod Major
Frequently asked questions
Can I take Etrasimod with Thioridazine?
MediHelp rates the interaction as major. Etrasimod and Thioridazine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Etrasimod can slow heart rate and delay AV conduction when started. Combined with thioridazine, a strongly QT-prolonging drug, the risk of torsades de pointes is higher, particularly with bradycardia.
How serious is the interaction between Etrasimod and Thioridazine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination where possible and choose a less QT-active antipsychotic. If it is essential, obtain a baseline ECG, monitor it after initiation and correct potassium and magnesium.
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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