Drug interactions
Fosaprepitant + Itraconazole
Severity: Moderate
Fosaprepitant and Itraconazole: 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 is converted to aprepitant, a CYP3A4 substrate, and itraconazole can raise aprepitant levels. The result may be more adverse effects such as fatigue, headache and hepatic enzyme elevations, though a single IV dose gives a limited effect.
What this interaction means in plain words
Fosaprepitant and Itraconazole 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 belongs to Gastrointestinal Tract; Itraconazole belongs to Anti Fungals.
Why it happens
Strong CYP3A4 inhibition decreases aprepitant clearance.
What to do
Monitor for aprepitant-related adverse effects, particularly with repeated dosing. Another antifungal is preferred if therapy is prolonged.
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 Itraconazole
- Alfuzosin + Itraconazole Contraindicated
- Alprazolam + Itraconazole Contraindicated
- Avanafil + Itraconazole Contraindicated
- Conivaptan + Itraconazole Contraindicated
- Dihydroergotamine intranasal + Itraconazole Contraindicated
- Dihydroergotamine + Itraconazole 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 Fosaprepitant with Itraconazole?
MediHelp rates the interaction as moderate. Fosaprepitant and Itraconazole 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 is converted to aprepitant, a CYP3A4 substrate, and itraconazole can raise aprepitant levels. The result may be more adverse effects such as fatigue, headache and hepatic enzyme elevations, though a single IV dose gives a limited effect.
How serious is the interaction between Fosaprepitant and Itraconazole?
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 aprepitant-related adverse effects, particularly with repeated dosing. Another antifungal is preferred if therapy is prolonged.
What other medicines interact with Itraconazole?
MediHelp also lists interactions of Itraconazole with, for example, Alfuzosin, Alprazolam, Avanafil. The full list is on the Itraconazole page.
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