Drug interactions
Erdafitinib + Zafirlukast
Severity: Moderate
Erdafitinib and Zafirlukast: moderate 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
Zafirlukast inhibits CYP2C9, the main enzyme clearing erdafitinib, so erdafitinib exposure may rise. This may increase toxicities such as hyperphosphatemia, ocular and skin or nail effects, and stomatitis.
What this interaction means in plain words
Erdafitinib and Zafirlukast can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Erdafitinib belongs to Oncology; Zafirlukast belongs to Respiratory.
Why it happens
Inhibition of CYP2C9-mediated erdafitinib metabolism by zafirlukast.
What to do
Monitor for erdafitinib adverse reactions, including serum phosphate and eye symptoms, and reduce the dose if toxicity occurs. Consider an alternative to zafirlukast such as montelukast.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Zafirlukast
- Pimozide + Zafirlukast Contraindicated
- Lomitapide + Zafirlukast Major
- Nilotinib + Zafirlukast Major
- Warfarin + Zafirlukast Major
- Apalutamide + Zafirlukast Moderate
- Carbamazepine + Zafirlukast Moderate
Other interactions of Erdafitinib
Frequently asked questions
Can I take Erdafitinib with Zafirlukast?
MediHelp rates the interaction as moderate. Erdafitinib and Zafirlukast can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Zafirlukast inhibits CYP2C9, the main enzyme clearing erdafitinib, so erdafitinib exposure may rise. This may increase toxicities such as hyperphosphatemia, ocular and skin or nail effects, and stomatitis.
How serious is the interaction between Erdafitinib and Zafirlukast?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for erdafitinib adverse reactions, including serum phosphate and eye symptoms, and reduce the dose if toxicity occurs. Consider an alternative to zafirlukast such as montelukast.
What other medicines interact with Zafirlukast?
MediHelp also lists interactions of Zafirlukast with, for example, Pimozide, Lomitapide, Nilotinib. The full list is on the Zafirlukast page.
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