Drug interactions
Lumefantrine + Thioridazine
Severity: Contraindicated
Lumefantrine and Thioridazine: 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
Lumefantrine prolongs QT and may inhibit CYP2D6, which can raise thioridazine levels. Together these effects substantially increase the risk of torsades de pointes.
What this interaction means in plain words
Lumefantrine 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.
Why it happens
Additive QT prolongation with lumefantrine-related CYP2D6 inhibition increasing thioridazine concentrations.
What to do
Avoid the combination and use an antimalarial or antipsychotic without QT liability. If unavoidable, monitor ECG and correct electrolytes.
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 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 Lumefantrine with Thioridazine?
MediHelp rates the interaction as contraindicated. Lumefantrine 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. Lumefantrine prolongs QT and may inhibit CYP2D6, which can raise thioridazine levels. Together these effects substantially increase the risk of torsades de pointes.
How serious is the interaction between Lumefantrine 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: Avoid the combination and use an antimalarial or antipsychotic without QT liability. If unavoidable, monitor ECG and correct electrolytes.
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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