Drug interactions
Fostamatinib + Midazolam
Severity: Moderate
Fostamatinib and Midazolam: 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
Fostamatinib's active metabolite, R406, inhibits CYP3A4 and can increase exposure to CYP3A4 substrates such as midazolam. This may lead to prolonged sedation.
What this interaction means in plain words
Fostamatinib and Midazolam 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; Midazolam belongs to Central Nervous System.
Why it happens
R406, the active metabolite of fostamatinib, inhibits CYP3A4, reducing midazolam metabolism.
What to do
Monitor for excess sedation and respiratory depression, and reduce the midazolam dose as needed. Consider a lower starting dose for sedation procedures.
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 Midazolam
- Atazanavir + Midazolam Contraindicated
- Cobicistat + Midazolam Contraindicated
- Darunavir + Midazolam Contraindicated
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Midazolam Contraindicated
- Fosamprenavir + Midazolam Contraindicated
- Indinavir + Midazolam Contraindicated
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 Midazolam?
MediHelp rates the interaction as moderate. Fostamatinib and Midazolam 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's active metabolite, R406, inhibits CYP3A4 and can increase exposure to CYP3A4 substrates such as midazolam. This may lead to prolonged sedation.
How serious is the interaction between Fostamatinib and Midazolam?
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 for excess sedation and respiratory depression, and reduce the midazolam dose as needed. Consider a lower starting dose for sedation procedures.
What other medicines interact with Midazolam?
MediHelp also lists interactions of Midazolam with, for example, Atazanavir, Cobicistat, Darunavir. The full list is on the Midazolam page.
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