Drug interactions
Deflazacort + Fosaprepitant
Severity: Moderate
Deflazacort and Fosaprepitant: 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
Fosaprepitant, converted to aprepitant, is a moderate CYP3A4 inhibitor and can raise deflazacort's active metabolite levels. Corticosteroid-related adverse effects may increase, although a single fosaprepitant dose gives a transient effect.
What this interaction means in plain words
Deflazacort and Fosaprepitant 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.
Deflazacort belongs to Miscellaneous; Fosaprepitant belongs to Gastrointestinal Tract.
Why it happens
Aprepitant temporarily inhibits CYP3A4, reducing clearance of deflazacort's active metabolite.
What to do
Reduce the deflazacort dose to one-third of the usual dose when coadministered with moderate CYP3A4 inhibitors, per labeling. Monitor for signs of corticosteroid excess.
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 Deflazacort
- Adenovirus types 4 and 7 live + Deflazacort Contraindicated
- Bcg vaccine live + Deflazacort Contraindicated
- Deflazacort + Influenza virus vaccine quadrivalent intranasal Contraindicated
- Deflazacort + Measles mumps and rubella vaccine Contraindicated
- Deflazacort + Measles mumps and rubella vaccine live Contraindicated
- Deflazacort + Measles mumps rubella and varicella vaccine live Contraindicated
Other interactions of Fosaprepitant
- Flibanserin + Fosaprepitant Contraindicated
- Fosaprepitant + Pimozide Contraindicated
- Alprazolam + Fosaprepitant Moderate
- Amiodarone + Fosaprepitant Moderate
- Amobarbital + Fosaprepitant Moderate
- Apalutamide + Fosaprepitant Moderate
Frequently asked questions
Can I take Deflazacort with Fosaprepitant?
MediHelp rates the interaction as moderate. Deflazacort and Fosaprepitant 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. Fosaprepitant, converted to aprepitant, is a moderate CYP3A4 inhibitor and can raise deflazacort's active metabolite levels. Corticosteroid-related adverse effects may increase, although a single fosaprepitant dose gives a transient effect.
How serious is the interaction between Deflazacort and Fosaprepitant?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Reduce the deflazacort dose to one-third of the usual dose when coadministered with moderate CYP3A4 inhibitors, per labeling. Monitor for signs of corticosteroid excess.
What other medicines interact with Deflazacort?
MediHelp also lists interactions of Deflazacort with, for example, Adenovirus types 4 and 7 live, Bcg vaccine live, Influenza virus vaccine quadrivalent intranasal. The full list is on the Deflazacort page.
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