Drug interactions
Cyclophosphamide + Tucatinib
Severity: Moderate
Cyclophosphamide and Tucatinib: 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
Tucatinib inhibits CYP3A4 and may alter cyclophosphamide metabolism. The net effect on active metabolite exposure is uncertain because cyclophosphamide is activated mainly by CYP2B6, but toxicity could change.
What this interaction means in plain words
Cyclophosphamide and Tucatinib 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; Tucatinib belongs to Oncology.
Why it happens
CYP3A4 inhibition by tucatinib may alter cyclophosphamide metabolism.
What to do
Monitor blood counts and for signs of cyclophosphamide toxicity. Reduce the cyclophosphamide dose if toxicity develops.
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 Tucatinib
- Cisapride + Tucatinib Contraindicated
- Eletriptan + Tucatinib Contraindicated
- Ergotamine + Tucatinib Contraindicated
- Flibanserin + Tucatinib Contraindicated
- Ranolazine + Tucatinib Contraindicated
- Amobarbital + Tucatinib Major
Frequently asked questions
Can I take Cyclophosphamide with Tucatinib?
MediHelp rates the interaction as moderate. Cyclophosphamide and Tucatinib 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. Tucatinib inhibits CYP3A4 and may alter cyclophosphamide metabolism. The net effect on active metabolite exposure is uncertain because cyclophosphamide is activated mainly by CYP2B6, but toxicity could change.
How serious is the interaction between Cyclophosphamide and Tucatinib?
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 cyclophosphamide toxicity. Reduce the cyclophosphamide dose if toxicity develops.
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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