Drug interactions
Diazepam + Fosaprepitant
Severity: Moderate
Diazepam 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, through its active form aprepitant, is a moderate CYP3A4 inhibitor after a single dose and may modestly raise diazepam exposure. This may cause more sedation, though the effect is usually short-lived and manageable.
What this interaction means in plain words
Diazepam 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.
Diazepam belongs to Musculoskeletal; Fosaprepitant belongs to Gastrointestinal Tract.
Why it happens
Aprepitant inhibits CYP3A4, reducing the metabolism of diazepam.
What to do
Monitor for increased sedation for several days after fosaprepitant and reduce the diazepam dose if needed.
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 Diazepam
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 Diazepam with Fosaprepitant?
MediHelp rates the interaction as moderate. Diazepam 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, through its active form aprepitant, is a moderate CYP3A4 inhibitor after a single dose and may modestly raise diazepam exposure. This may cause more sedation, though the effect is usually short-lived and manageable.
How serious is the interaction between Diazepam 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: Monitor for increased sedation for several days after fosaprepitant and reduce the diazepam dose if needed.
What other medicines interact with Diazepam?
MediHelp also lists interactions of Diazepam with, for example, Calcium / magnesium / potassium / sodium oxybates, Alfentanil, Alprazolam. The full list is on the Diazepam page.
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