Drug interactions
Citalopram + Thioridazine
Severity: Contraindicated
Citalopram and Thioridazine: contraindicated interaction.
Last updated Sources: UK 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
Thioridazine markedly prolongs the QT interval and is contraindicated with other drugs that prolong QT. Adding citalopram increases the risk of torsades de pointes and sudden cardiac death.
What this interaction means in plain words
Citalopram 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.
Citalopram belongs to Central Nervous System; Thioridazine belongs to Central Nervous System.
Why it happens
Additive QT prolongation; thioridazine is also metabolized by CYP2D6, which can be weakly inhibited by citalopram.
What to do
Do not coadminister. Choose an alternative antipsychotic or antidepressant 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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References
Other interactions of Citalopram
- Cisapride + Citalopram Contraindicated
- Citalopram + Dronedarone Contraindicated
- Citalopram + Escitalopram Contraindicated
- Citalopram + Isocarboxazid Contraindicated
- Citalopram + Methylene blue Contraindicated
- Citalopram + Phenelzine Contraindicated
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 Citalopram with Thioridazine?
MediHelp rates the interaction as contraindicated. Citalopram 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 markedly prolongs the QT interval and is contraindicated with other drugs that prolong QT. Adding citalopram increases the risk of torsades de pointes and sudden cardiac death.
How serious is the interaction between Citalopram 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 coadminister. Choose an alternative antipsychotic or antidepressant with lower QT risk.
What other medicines interact with Citalopram?
MediHelp also lists interactions of Citalopram with, for example, Cisapride, Dronedarone, Escitalopram. The full list is on the Citalopram page.
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