Drug interactions
Aprepitant + St john's wort
Severity: Major
Aprepitant and St john's wort: major interaction.
Last updated Sources: US FDA label
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
St John's wort can lower aprepitant concentrations and weaken antiemetic protection. This could result in breakthrough nausea and vomiting.
What this interaction means in plain words
Aprepitant and St john's wort can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Why it happens
St John's wort induces CYP3A4, increasing aprepitant metabolism.
What to do
Avoid concurrent use and stop the herbal product before starting aprepitant. If it continues, monitor for loss of antiemetic effect.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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References
Other interactions of Aprepitant
- Aprepitant + Lomitapide Contraindicated
- Aprepitant + Pimozide Contraindicated
- Aprepitant + Avapritinib Major
- Aprepitant + Bosutinib Major
- Aprepitant + Carbamazepine Major
- Aprepitant + Cobicistat Major
Frequently asked questions
Can I take Aprepitant with St john's wort?
MediHelp rates the interaction as major. Aprepitant and St john's wort can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. St John's wort can lower aprepitant concentrations and weaken antiemetic protection. This could result in breakthrough nausea and vomiting.
How serious is the interaction between Aprepitant and St john's wort?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid concurrent use and stop the herbal product before starting aprepitant. If it continues, monitor for loss of antiemetic effect.
What other medicines interact with Aprepitant?
MediHelp also lists interactions of Aprepitant with, for example, Lomitapide, Pimozide, Avapritinib. The full list is on the Aprepitant page.
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