Ifosfamide Injection and Aprepitant: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Aprepitant
Ifosfamide Injection
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Increased chemotherapeutic agent exposure
Interaction Deep Dive
Coadministration of aprepitant or fosaprepitant with chemotherapeutic agents that are metabolized by CYP3A4, may increase the exposure of these agents. Monitor for chemotherapeutic-related adverse reactions when coadministered with aprepitant or fosaprepitant. No dosage adjustment is needed for etoposide, vinorelbine, PACLitaxel and DOCEtaxel1.
Why it happens (mechanism)
Inhibition of CYP3A4 mediated metabolism by aprepitant
Common questions
Can I take Ifosfamide Injection and Aprepitant together?
Increased chemotherapeutic agent exposure Always confirm with your pharmacist or prescriber before making any change.
How serious is the Ifosfamide Injection and Aprepitant interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Ifosfamide Injection or Aprepitant need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (1)
- Product Information: FOCINVEZ intravenous injection, fosaprepitant intravenous injection. Spes Pharmaceuticals Inc (per FDA), North Brunswick, NJ, 2023. DailyMed
Keep reading about Aprepitant
Keep reading about Ifosfamide Injection
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