Drug interactions
Erdafitinib + Ketoconazole
Severity: Major
Erdafitinib and Ketoconazole: 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
Ketoconazole increases erdafitinib exposure, which may worsen hyperphosphatemia, ocular toxicity, stomatitis and skin or nail effects.
What this interaction means in plain words
Erdafitinib and Ketoconazole 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.
Erdafitinib belongs to Oncology; Ketoconazole belongs to Anti Fungals.
Why it happens
Ketoconazole inhibits CYP3A4 and CYP2C9, which are both involved in erdafitinib clearance.
What to do
Avoid if possible; otherwise monitor closely for adverse reactions and reduce the erdafitinib dose as needed. Re-escalate if the inhibitor is stopped and there is no toxicity.
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 Ketoconazole
- Alfuzosin + Ketoconazole Contraindicated
- Alprazolam + Ketoconazole Contraindicated
- Avanafil + Ketoconazole Contraindicated
- Conivaptan + Ketoconazole Contraindicated
- Dihydroergotamine intranasal + Ketoconazole Contraindicated
- Dihydroergotamine + Ketoconazole Contraindicated
Other interactions of Erdafitinib
Frequently asked questions
Can I take Erdafitinib with Ketoconazole?
MediHelp rates the interaction as major. Erdafitinib and Ketoconazole 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. Ketoconazole increases erdafitinib exposure, which may worsen hyperphosphatemia, ocular toxicity, stomatitis and skin or nail effects.
How serious is the interaction between Erdafitinib and Ketoconazole?
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 if possible; otherwise monitor closely for adverse reactions and reduce the erdafitinib dose as needed. Re-escalate if the inhibitor is stopped and there is no toxicity.
What other medicines interact with Ketoconazole?
MediHelp also lists interactions of Ketoconazole with, for example, Alfuzosin, Alprazolam, Avanafil. The full list is on the Ketoconazole page.
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