Drug interactions
Idelalisib + Ondansetron
Severity: Moderate
Idelalisib and Ondansetron: 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
Idelalisib is a strong CYP3A inhibitor and can raise ondansetron exposure. Because ondansetron is metabolized by several enzymes and CYP3A4 is only one pathway, the increase is likely modest, though QT prolongation is a dose-related concern.
What this interaction means in plain words
Idelalisib and Ondansetron 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.
Idelalisib belongs to Oncology; Ondansetron belongs to Gastrointestinal Tract.
Why it happens
Inhibition of CYP3A4-mediated ondansetron metabolism by idelalisib.
What to do
Use the lowest effective ondansetron dose and monitor for QT prolongation, especially in patients with other cardiac risk factors. Check the ECG if multiple doses are required.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Idelalisib and Ondansetron, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 14 days on the web. No card needed.
Other interactions of Ondansetron
- Apomorphine + Ondansetron Contraindicated
- Ondansetron + Thioridazine Contraindicated
- Ondansetron + Vandetanib Contraindicated
- Adagrasib + Ondansetron Major
- Amiodarone + Ondansetron Major
- Amisulpride + Ondansetron Major
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 Ondansetron?
MediHelp rates the interaction as moderate. Idelalisib and Ondansetron 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. Idelalisib is a strong CYP3A inhibitor and can raise ondansetron exposure. Because ondansetron is metabolized by several enzymes and CYP3A4 is only one pathway, the increase is likely modest, though QT prolongation is a dose-related concern.
How serious is the interaction between Idelalisib and Ondansetron?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use the lowest effective ondansetron dose and monitor for QT prolongation, especially in patients with other cardiac risk factors. Check the ECG if multiple doses are required.
What other medicines interact with Ondansetron?
MediHelp also lists interactions of Ondansetron with, for example, Apomorphine, Thioridazine, Vandetanib. The full list is on the Ondansetron page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
