Drug interactions
Fostamatinib + Imatinib
Severity: Moderate
Fostamatinib and Imatinib: 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
Imatinib inhibits CYP3A4, which may raise exposure to R406, the active metabolite of fostamatinib. This may increase hypertension, diarrhea, hepatotoxicity and neutropenia.
What this interaction means in plain words
Fostamatinib and Imatinib 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.
Fostamatinib belongs to Oncology; Imatinib belongs to Oncology.
Why it happens
Imatinib inhibits CYP3A4 metabolism of R406, raising its exposure.
What to do
Monitor blood pressure, liver tests and neutrophil count, and reduce the fostamatinib dose if adverse effects appear.
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 Imatinib
- Imatinib + Lomitapide Contraindicated
- Imatinib + Lonafarnib Contraindicated
- Amobarbital + Imatinib Major
- Apalutamide + Imatinib Major
- Avapritinib + Imatinib Major
- Benzhydrocodone / acetaminophen + Imatinib Major
Other interactions of Fostamatinib
- Colchicine + Fostamatinib Major
- Fostamatinib + Phenytoin Major
- Amobarbital + Fostamatinib Moderate
- Apalutamide + Fostamatinib Moderate
- Atorvastatin + Fostamatinib Moderate
- Bosentan + Fostamatinib Moderate
Frequently asked questions
Can I take Fostamatinib with Imatinib?
MediHelp rates the interaction as moderate. Fostamatinib and Imatinib 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. Imatinib inhibits CYP3A4, which may raise exposure to R406, the active metabolite of fostamatinib. This may increase hypertension, diarrhea, hepatotoxicity and neutropenia.
How serious is the interaction between Fostamatinib and Imatinib?
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 pressure, liver tests and neutrophil count, and reduce the fostamatinib dose if adverse effects appear.
What other medicines interact with Imatinib?
MediHelp also lists interactions of Imatinib with, for example, Lomitapide, Lonafarnib, Amobarbital. The full list is on the Imatinib page.
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