Drug interactions
Cyclophosphamide + Idelalisib
Severity: Moderate
Cyclophosphamide and Idelalisib: 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 alter cyclophosphamide metabolism. Cyclophosphamide is activated mainly by CYP2B6 with contribution from CYP3A4, so the net effect on active metabolite exposure is uncertain. Both drugs also cause myelosuppression and infection risk.
What this interaction means in plain words
Cyclophosphamide and Idelalisib 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.
Cyclophosphamide belongs to Oncology; Idelalisib belongs to Oncology.
Why it happens
CYP3A4 inhibition by idelalisib alters cyclophosphamide activation and detoxification, with additive pharmacodynamic toxicity.
What to do
Monitor blood counts and for signs of excess toxicity or reduced effect. Use prophylaxis for infection as clinically indicated.
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 Cyclophosphamide
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 Cyclophosphamide with Idelalisib?
MediHelp rates the interaction as moderate. Cyclophosphamide and Idelalisib 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 alter cyclophosphamide metabolism. Cyclophosphamide is activated mainly by CYP2B6 with contribution from CYP3A4, so the net effect on active metabolite exposure is uncertain. Both drugs also cause myelosuppression and infection risk.
How serious is the interaction between Cyclophosphamide and Idelalisib?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor blood counts and for signs of excess toxicity or reduced effect. Use prophylaxis for infection as clinically indicated.
What other medicines interact with Cyclophosphamide?
MediHelp also lists interactions of Cyclophosphamide with, for example, Adenovirus types 4 and 7 live, Belatacept, Bendamustine. The full list is on the Cyclophosphamide page.
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