Drug interactions
Amitriptyline + Thioridazine
Severity: Contraindicated
Amitriptyline 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 is a strong QT-prolonging antipsychotic, and amitriptyline adds further QT and conduction effects. The combination markedly increases the risk of torsades de pointes and sudden cardiac death.
What this interaction means in plain words
Amitriptyline 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.
Amitriptyline belongs to Central Nervous System; Thioridazine belongs to Central Nervous System.
Why it happens
Additive QT prolongation, with thioridazine also inhibiting CYP2D6 and raising amitriptyline levels.
What to do
Do not combine these drugs; select an alternative antipsychotic or antidepressant with less cardiac liability.
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 Amitriptyline
- Amitriptyline + Isocarboxazid Contraindicated
- Amitriptyline + Methylene blue Contraindicated
- Amitriptyline + Phenelzine Contraindicated
- Amitriptyline + Pimozide Contraindicated
- Amitriptyline + Procarbazine Contraindicated
- Amitriptyline + Safinamide Contraindicated
Other interactions of Thioridazine
- Abiraterone + Thioridazine Contraindicated
- Adagrasib + Thioridazine Contraindicated
- Amiodarone + Thioridazine Contraindicated
- Amisulpride + Thioridazine Contraindicated
- Amoxapine + Thioridazine Contraindicated
- Anagrelide + Thioridazine Contraindicated
Frequently asked questions
Can I take Amitriptyline with Thioridazine?
MediHelp rates the interaction as contraindicated. Amitriptyline 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 is a strong QT-prolonging antipsychotic, and amitriptyline adds further QT and conduction effects. The combination markedly increases the risk of torsades de pointes and sudden cardiac death.
How serious is the interaction between Amitriptyline 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 these drugs; select an alternative antipsychotic or antidepressant with less cardiac liability.
What other medicines interact with Amitriptyline?
MediHelp also lists interactions of Amitriptyline with, for example, Isocarboxazid, Methylene blue, Phenelzine. The full list is on the Amitriptyline page.
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