Drug interactions
Ketoconazole + Zafirlukast
Severity: Minor
Ketoconazole and Zafirlukast: minor 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
Ketoconazole is metabolized partly by CYP3A4, which zafirlukast may weakly inhibit. A clinically relevant rise in ketoconazole exposure is unlikely, though both drugs can affect the liver.
What this interaction means in plain words
Ketoconazole and Zafirlukast have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Ketoconazole belongs to Anti Fungals; Zafirlukast belongs to Respiratory.
Why it happens
Possible weak CYP3A4 inhibition by zafirlukast reducing ketoconazole clearance.
What to do
No dose change is needed. Monitor liver function if both are used together, since both can cause hepatotoxicity.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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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 Ketoconazole
- Alfuzosin + Ketoconazole Contraindicated
- Alprazolam + Ketoconazole Contraindicated
- Avanafil + Ketoconazole Contraindicated
- Conivaptan + Ketoconazole Contraindicated
- Dihydroergotamine intranasal + Ketoconazole Contraindicated
- Dihydroergotamine + Ketoconazole Contraindicated
Frequently asked questions
Can I take Ketoconazole with Zafirlukast?
MediHelp rates the interaction as minor. Ketoconazole and Zafirlukast have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Ketoconazole is metabolized partly by CYP3A4, which zafirlukast may weakly inhibit. A clinically relevant rise in ketoconazole exposure is unlikely, though both drugs can affect the liver.
How serious is the interaction between Ketoconazole and Zafirlukast?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No dose change is needed. Monitor liver function if both are used together, since both can cause hepatotoxicity.
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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