Drug interactions
Idelalisib + Ketoconazole
Severity: Major
Idelalisib and Ketoconazole: major 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 idelalisib exposure. This may increase risks of hepatotoxicity, severe diarrhea or colitis, and pneumonitis.
What this interaction means in plain words
Idelalisib and Ketoconazole can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Idelalisib belongs to Oncology; Ketoconazole belongs to Anti Fungals.
Why it happens
Strong CYP3A4 inhibition by ketoconazole reduces the clearance of idelalisib (also partly metabolized by aldehyde oxidase and UGT1A4).
What to do
Avoid the combination where an alternative antifungal exists. If it is used, monitor liver enzymes and for diarrhea and respiratory symptoms, and interrupt or reduce idelalisib per labeling.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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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 Idelalisib
- Alfuzosin + Idelalisib Contraindicated
- Cisapride + Idelalisib Contraindicated
- Dihydroergotamine + Idelalisib Contraindicated
- Dronedarone + Idelalisib Contraindicated
- Eletriptan + Idelalisib Contraindicated
- Eplerenone + Idelalisib Contraindicated
Frequently asked questions
Can I take Idelalisib with Ketoconazole?
MediHelp rates the interaction as major. Idelalisib and Ketoconazole can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Ketoconazole increases idelalisib exposure. This may increase risks of hepatotoxicity, severe diarrhea or colitis, and pneumonitis.
How serious is the interaction between Idelalisib and Ketoconazole?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination where an alternative antifungal exists. If it is used, monitor liver enzymes and for diarrhea and respiratory symptoms, and interrupt or reduce idelalisib per labeling.
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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