Drug interactions
Bosentan + Fostamatinib
Severity: Moderate
Bosentan and Fostamatinib: 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
The active metabolite of fostamatinib, R406, is metabolised by CYP3A4, so bosentan may reduce its exposure. This could weaken the platelet-raising effect.
What this interaction means in plain words
Bosentan and Fostamatinib 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.
Bosentan belongs to Miscellaneous; Fostamatinib belongs to Oncology.
Why it happens
Bosentan induces CYP3A4, increasing metabolism of R406, the active metabolite of fostamatinib.
What to do
Monitor platelet counts and adjust fostamatinib dosing as needed if response declines.
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 Bosentan
- Bosentan + Cyclosporin Contraindicated
- Bosentan + Cyclosporine Contraindicated
- Bosentan + Glyburide Contraindicated
- Bosentan + Glyburide-metformin Contraindicated
- Bosentan + Lonafarnib Contraindicated
- Bosentan + Sparsentan Contraindicated
Other interactions of Fostamatinib
- Colchicine + Fostamatinib Major
- Fostamatinib + Phenytoin Major
- Amobarbital + Fostamatinib Moderate
- Apalutamide + Fostamatinib Moderate
- Atorvastatin + Fostamatinib Moderate
- Carbamazepine + Fostamatinib Moderate
Frequently asked questions
Can I take Bosentan with Fostamatinib?
MediHelp rates the interaction as moderate. Bosentan and Fostamatinib 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. The active metabolite of fostamatinib, R406, is metabolised by CYP3A4, so bosentan may reduce its exposure. This could weaken the platelet-raising effect.
How serious is the interaction between Bosentan and Fostamatinib?
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 platelet counts and adjust fostamatinib dosing as needed if response declines.
What other medicines interact with Bosentan?
MediHelp also lists interactions of Bosentan with, for example, Cyclosporin, Cyclosporine, Glyburide. The full list is on the Bosentan page.
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