Drug interactions
Erlotinib + Ketoconazole
Severity: Moderate
Erlotinib and Ketoconazole: 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
Ketoconazole increases erlotinib exposure, raising the likelihood of rash, diarrhea and other adverse effects.
What this interaction means in plain words
Erlotinib and Ketoconazole 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.
Erlotinib belongs to Oncology; Ketoconazole belongs to Anti Fungals.
Why it happens
Ketoconazole inhibits CYP3A4 metabolism of erlotinib and may also inhibit P-glycoprotein.
What to do
Avoid the combination if possible. If used, monitor for erlotinib toxicity and reduce the dose in 50 mg steps if severe reactions occur.
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 Ketoconazole
- Alfuzosin + Ketoconazole Contraindicated
- Alprazolam + Ketoconazole Contraindicated
- Avanafil + Ketoconazole Contraindicated
- Conivaptan + Ketoconazole Contraindicated
- Dihydroergotamine intranasal + Ketoconazole Contraindicated
- Dihydroergotamine + Ketoconazole Contraindicated
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 Ketoconazole?
MediHelp rates the interaction as moderate. Erlotinib and Ketoconazole 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. Ketoconazole increases erlotinib exposure, raising the likelihood of rash, diarrhea and other adverse effects.
How serious is the interaction between Erlotinib and Ketoconazole?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination if possible. If used, monitor for erlotinib toxicity and reduce the dose in 50 mg steps if severe reactions occur.
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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