Drug interactions
Etonogestrel + Fosaprepitant
Severity: Moderate
Etonogestrel 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
Aprepitant given as fosaprepitant can induce CYP3A4 over time and has been shown to reduce hormonal contraceptive exposure, so contraceptive reliability may fall for a period after dosing.
What this interaction means in plain words
Etonogestrel 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.
Etonogestrel belongs to Endocrine; Fosaprepitant belongs to Gastrointestinal Tract.
Why it happens
Aprepitant induces CYP3A4 and other enzymes, increasing metabolism of progestins.
What to do
Use an additional barrier method during treatment and for about 1 month after the last dose.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Etonogestrel and Fosaprepitant, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Etonogestrel
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 Etonogestrel with Fosaprepitant?
MediHelp rates the interaction as moderate. Etonogestrel 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. Aprepitant given as fosaprepitant can induce CYP3A4 over time and has been shown to reduce hormonal contraceptive exposure, so contraceptive reliability may fall for a period after dosing.
How serious is the interaction between Etonogestrel 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: Use an additional barrier method during treatment and for about 1 month after the last dose.
What other medicines interact with Etonogestrel?
MediHelp also lists interactions of Etonogestrel with, for example, Amobarbital, Armodafinil, Bosentan. The full list is on the Etonogestrel page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
