Drug interactions
Ketoconazole + Osimertinib
Severity: Moderate
Ketoconazole and Osimertinib: 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 may modestly increase osimertinib exposure. Osimertinib can prolong the QT interval, so higher levels could add to that risk. The effect was not clinically significant in a labeling study.
What this interaction means in plain words
Ketoconazole and Osimertinib 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 belongs to Anti Fungals; Osimertinib belongs to Oncology.
Why it happens
CYP3A4 inhibition by ketoconazole may slightly reduce osimertinib metabolism.
What to do
No dose change is required, but monitor ECG and electrolytes if other QT-prolonging drugs are used.
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 Osimertinib
Frequently asked questions
Can I take Ketoconazole with Osimertinib?
MediHelp rates the interaction as moderate. Ketoconazole and Osimertinib 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 may modestly increase osimertinib exposure. Osimertinib can prolong the QT interval, so higher levels could add to that risk. The effect was not clinically significant in a labeling study.
How serious is the interaction between Ketoconazole and Osimertinib?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No dose change is required, but monitor ECG and electrolytes if other QT-prolonging drugs are used.
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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