Drug interactions
Fluconazole + Fosaprepitant
Severity: Moderate
Fluconazole 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 is converted to aprepitant, which is a CYP3A4 substrate. Fluconazole, a moderate CYP3A4 inhibitor, can raise aprepitant exposure and increase the likelihood of adverse effects such as fatigue, headache, and gastrointestinal upset. A single intravenous fosaprepitant dose is usually well tolerated, so the effect is typically modest.
What this interaction means in plain words
Fluconazole 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.
Fluconazole belongs to Anti Fungals; Fosaprepitant belongs to Gastrointestinal Tract.
Why it happens
Fluconazole inhibits CYP3A4, reducing the metabolic clearance of aprepitant, the active metabolite of fosaprepitant.
What to do
No routine dose change is needed; monitor for aprepitant-related adverse effects such as somnolence, dizziness, and GI symptoms. Be more vigilant with repeated dosing or when other CYP3A4 inhibitors are also present.
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 Fluconazole
- Dihydroergotamine intranasal + Fluconazole Contraindicated
- Dihydroergotamine + Fluconazole Contraindicated
- Dofetilide + Fluconazole Contraindicated
- Domperidone + Fluconazole Contraindicated
- Dronedarone + Fluconazole Contraindicated
- Erythromycin + Fluconazole 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 Fluconazole with Fosaprepitant?
MediHelp rates the interaction as moderate. Fluconazole 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 is converted to aprepitant, which is a CYP3A4 substrate. Fluconazole, a moderate CYP3A4 inhibitor, can raise aprepitant exposure and increase the likelihood of adverse effects such as fatigue, headache, and gastrointestinal upset. A single intravenous fosaprepitant dose is usually well tolerated, so the effect is typically modest.
How serious is the interaction between Fluconazole 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: No routine dose change is needed; monitor for aprepitant-related adverse effects such as somnolence, dizziness, and GI symptoms. Be more vigilant with repeated dosing or when other CYP3A4 inhibitors are also present.
What other medicines interact with Fluconazole?
MediHelp also lists interactions of Fluconazole with, for example, Dihydroergotamine intranasal, Dihydroergotamine, Dofetilide. The full list is on the Fluconazole page.
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