Drug interactions
Clozapine + Quizartinib
Severity: Major
Clozapine and Quizartinib: 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
Quizartinib has a boxed warning for QT prolongation, torsades de pointes and cardiac arrest, and clozapine adds to QT risk. The combination increases the chance of serious arrhythmia.
What this interaction means in plain words
Clozapine and Quizartinib 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; Quizartinib belongs to Oncology.
Why it happens
Additive prolongation of cardiac repolarization (QTc).
What to do
Avoid the combination if possible; otherwise monitor ECG more frequently and keep potassium and magnesium normal. Reduce or hold quizartinib if QTc rises markedly.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Clozapine and Quizartinib, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
References
- Clozapine Viatris 100 mg Orodispersible Tablets - SmPC sections 4.3/4.5 (class statement: medicines known to increase QTc interval; "caution should be exercised when clozapine is prescribed with medicines known to increase QTc interval, or causing electrolyte imbalance.") — 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 Quizartinib
- Quizartinib + Thioridazine Contraindicated
- Quizartinib + Ziprasidone Contraindicated
- Alfuzosin + Quizartinib Major
- Amiodarone + Quizartinib Major
- Amitriptyline + Quizartinib Major
- Amobarbital + Quizartinib Major
Frequently asked questions
Can I take Clozapine with Quizartinib?
MediHelp rates the interaction as major. Clozapine and Quizartinib 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. Quizartinib has a boxed warning for QT prolongation, torsades de pointes and cardiac arrest, and clozapine adds to QT risk. The combination increases the chance of serious arrhythmia.
How serious is the interaction between Clozapine and Quizartinib?
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 if possible; otherwise monitor ECG more frequently and keep potassium and magnesium normal. Reduce or hold quizartinib if QTc rises markedly.
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.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
