Drug interactions
Clozapine + Dosulepin
Severity: Major
Clozapine and Dosulepin: major 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
Dosulepin is a sedating tricyclic antidepressant with strong anticholinergic activity. With clozapine it increases sedation, anticholinergic effects, seizure risk and QT effects, and may also raise clozapine levels.
What this interaction means in plain words
Clozapine and Dosulepin 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.
Clozapine belongs to Central Nervous System; Dosulepin belongs to Central Nervous System.
Why it happens
Additive CNS depression, anticholinergic effects, seizure threshold lowering and QT prolongation.
What to do
Avoid the combination where possible, or use low doses with monitoring of sedation, bowel function, ECG and seizure activity. Consider clozapine levels if toxicity is suspected.
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
- Clozapine Viatris 100 mg Orodispersible Tablets - SmPC sections 4.3/4.5 (class statement: tricyclic antidepressants; "With tricyclic antidepressants, phenothiazines and type 1C anti-arrhythmics, which are known to bind to cytochrome P450 2D6, no clinically relevant interactions") — electronic medicines compendium (UK SmPC)
Other interactions of Clozapine
- Clozapine + Deferiprone Contraindicated
- Clozapine + Irinotecan Contraindicated
- Clozapine + Pimozide Contraindicated
- Clozapine + Thioridazine Contraindicated
- Acalabrutinib + Clozapine Major
- Adagrasib + Clozapine Major
Other interactions of Dosulepin
- Dosulepin + Isocarboxazid Contraindicated
- Dosulepin + Phenelzine Contraindicated
- Dosulepin + Thioridazine Contraindicated
- Dosulepin + Tranylcypromine Contraindicated
- Amitriptyline + Dosulepin Major
- Buprenorphine + Dosulepin Major
Frequently asked questions
Can I take Clozapine with Dosulepin?
MediHelp rates the interaction as major. Clozapine and Dosulepin 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. Dosulepin is a sedating tricyclic antidepressant with strong anticholinergic activity. With clozapine it increases sedation, anticholinergic effects, seizure risk and QT effects, and may also raise clozapine levels.
How serious is the interaction between Clozapine and Dosulepin?
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, or use low doses with monitoring of sedation, bowel function, ECG and seizure activity. Consider clozapine levels if toxicity is suspected.
What other medicines interact with Clozapine?
MediHelp also lists interactions of Clozapine with, for example, Deferiprone, Irinotecan, Pimozide. The full list is on the Clozapine page.
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