Drug interactions
Gilteritinib + Posaconazole
Severity: Major
Gilteritinib and Posaconazole: 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 raises gilteritinib concentrations through strong CYP3A4 inhibition, and both drugs can prolong the QT interval. The result may be greater gilteritinib toxicity, including QT prolongation, differentiation syndrome and hepatotoxicity.
What this interaction means in plain words
Gilteritinib and Posaconazole 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.
Gilteritinib belongs to Oncology; Posaconazole belongs to Anti Fungals.
Why it happens
Posaconazole inhibits CYP3A4 and P-gp, which increases gilteritinib exposure, and both drugs have additive QTc-prolonging effects.
What to do
Use an alternative antifungal if feasible. If combined, obtain ECGs and monitor electrolytes and for gilteritinib toxicity, and interrupt or reduce the gilteritinib dose if serious toxicity occurs.
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 Gilteritinib
- Gilteritinib + Pimozide Contraindicated
- Amiodarone + Gilteritinib Major
- Amisulpride + Gilteritinib Major
- Amitriptyline + Gilteritinib Major
- Anagrelide + Gilteritinib Major
- Apalutamide + Gilteritinib Major
Frequently asked questions
Can I take Gilteritinib with Posaconazole?
MediHelp rates the interaction as major. Gilteritinib and Posaconazole 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 raises gilteritinib concentrations through strong CYP3A4 inhibition, and both drugs can prolong the QT interval. The result may be greater gilteritinib toxicity, including QT prolongation, differentiation syndrome and hepatotoxicity.
How serious is the interaction between Gilteritinib and Posaconazole?
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 an alternative antifungal if feasible. If combined, obtain ECGs and monitor electrolytes and for gilteritinib toxicity, and interrupt or reduce the gilteritinib dose if serious toxicity occurs.
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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