Drug interactions
Dosulepin + Thioridazine
Severity: Contraindicated
Dosulepin 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
Both drugs can prolong the QT interval, and thioridazine carries a boxed warning for torsades de pointes. Combined use increases the risk of life-threatening arrhythmia, along with additive anticholinergic and sedative effects.
What this interaction means in plain words
Dosulepin 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.
Dosulepin belongs to Central Nervous System; Thioridazine belongs to Central Nervous System.
Why it happens
Additive cardiac potassium channel blockade, with possible CYP2D6 competition raising tricyclic and thioridazine levels.
What to do
Avoid the combination; choose an antidepressant or antipsychotic with lower QT liability. If any overlap occurs, obtain an 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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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 Dosulepin
- Dosulepin + Isocarboxazid Contraindicated
- Dosulepin + Phenelzine Contraindicated
- Dosulepin + Tranylcypromine Contraindicated
- Amitriptyline + Dosulepin Major
- Buprenorphine + Dosulepin Major
- Chlorpromazine + Dosulepin Major
Frequently asked questions
Can I take Dosulepin with Thioridazine?
MediHelp rates the interaction as contraindicated. Dosulepin 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. Both drugs can prolong the QT interval, and thioridazine carries a boxed warning for torsades de pointes. Combined use increases the risk of life-threatening arrhythmia, along with additive anticholinergic and sedative effects.
How serious is the interaction between Dosulepin 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; choose an antidepressant or antipsychotic with lower QT liability. If any overlap occurs, obtain an 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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