Drug interactions
Clozapine + Trazodone
Severity: Major
Clozapine and Trazodone: major 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
Both agents can prolong QTc, and clozapine also carries risks of myocarditis, orthostatic hypotension and sedation. Together they can add to arrhythmia risk and to hypotension and sedation.
What this interaction means in plain words
Clozapine and Trazodone 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; Trazodone belongs to Central Nervous System.
Why it happens
Additive QT prolongation and additive alpha-blockade and sedative effects; trazodone may also affect clozapine levels via CYP inhibition.
What to do
Use only when needed, with a baseline ECG and electrolyte correction. Monitor blood pressure, sedation and QTc, and review clozapine levels if toxicity appears.
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
Other interactions of Trazodone
- Arsenic trioxide + Trazodone Contraindicated
- Ibutilide + Trazodone Contraindicated
- Isocarboxazid + Trazodone Contraindicated
- Levoketoconazole + Trazodone Contraindicated
- Methylene blue + Trazodone Contraindicated
- Phenelzine + Trazodone Contraindicated
Other interactions of Clozapine
- Clozapine + Deferiprone Contraindicated
- Clozapine + Irinotecan Contraindicated
- Clozapine + Pimozide Contraindicated
- Clozapine + Thioridazine Contraindicated
- Acalabrutinib + Clozapine Major
- Adagrasib + Clozapine Major
Frequently asked questions
Can I take Clozapine with Trazodone?
MediHelp rates the interaction as major. Clozapine and Trazodone 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. Both agents can prolong QTc, and clozapine also carries risks of myocarditis, orthostatic hypotension and sedation. Together they can add to arrhythmia risk and to hypotension and sedation.
How serious is the interaction between Clozapine and Trazodone?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use only when needed, with a baseline ECG and electrolyte correction. Monitor blood pressure, sedation and QTc, and review clozapine levels if toxicity appears.
What other medicines interact with Trazodone?
MediHelp also lists interactions of Trazodone with, for example, Arsenic trioxide, Ibutilide, Isocarboxazid. The full list is on the Trazodone page.
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