Drug interactions
Erlotinib + Zafirlukast
Severity: Minor
Erlotinib 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
Erlotinib is metabolized mainly by CYP3A4, so inhibitors can increase exposure and toxicity such as rash and diarrhea. Zafirlukast's weak inhibition makes a notable change unlikely.
What this interaction means in plain words
Erlotinib 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.
Erlotinib belongs to Oncology; Zafirlukast belongs to Respiratory.
Why it happens
Weak CYP3A4 inhibition by zafirlukast may slightly decrease erlotinib metabolism.
What to do
Monitor for rash, diarrhea and interstitial lung symptoms. Reduce the erlotinib dose if severe toxicity occurs.
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 Erlotinib
- Amobarbital + Erlotinib Major
- Apalutamide + Erlotinib Major
- Carbamazepine + Erlotinib Major
- Cobicistat + Erlotinib Major
- Darunavir + Erlotinib Major
- Dexlansoprazole + Erlotinib Major
Frequently asked questions
Can I take Erlotinib with Zafirlukast?
MediHelp rates the interaction as minor. Erlotinib 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. Erlotinib is metabolized mainly by CYP3A4, so inhibitors can increase exposure and toxicity such as rash and diarrhea. Zafirlukast's weak inhibition makes a notable change unlikely.
How serious is the interaction between Erlotinib 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: Monitor for rash, diarrhea and interstitial lung symptoms. Reduce the erlotinib dose if severe toxicity occurs.
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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