Drug interactions
Posaconazole + Quizartinib
Severity: Major
Posaconazole and Quizartinib: major 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
Posaconazole increases quizartinib exposure, raising the risk of QT prolongation and torsades de pointes. Both drugs also prolong QT directly.
What this interaction means in plain words
Posaconazole 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.
Posaconazole belongs to Anti Fungals; Quizartinib belongs to Oncology.
Why it happens
Strong CYP3A4 inhibition reduces quizartinib clearance, with additive QT effects.
What to do
Reduce the quizartinib dose per labeling for strong CYP3A inhibitors, or interrupt it if already at the lowest dose. Monitor ECG and electrolytes, and restore the prior dose after stopping posaconazole.
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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Other interactions of Posaconazole
- Artemether + Posaconazole Contraindicated
- Avanafil + Posaconazole Contraindicated
- Cobimetinib + Posaconazole Contraindicated
- Conivaptan + Posaconazole Contraindicated
- Dihydroergotamine intranasal + Posaconazole Contraindicated
- Dihydroergotamine + Posaconazole Contraindicated
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 Posaconazole with Quizartinib?
MediHelp rates the interaction as major. Posaconazole 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. Posaconazole increases quizartinib exposure, raising the risk of QT prolongation and torsades de pointes. Both drugs also prolong QT directly.
How serious is the interaction between Posaconazole 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: Reduce the quizartinib dose per labeling for strong CYP3A inhibitors, or interrupt it if already at the lowest dose. Monitor ECG and electrolytes, and restore the prior dose after stopping posaconazole.
What other medicines interact with Posaconazole?
MediHelp also lists interactions of Posaconazole with, for example, Artemether, Avanafil, Cobimetinib. The full list is on the Posaconazole page.
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