Drug interactions
Paclitaxel + St john's wort
Severity: Major
Paclitaxel and St john's wort: major 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
St John's wort induces paclitaxel metabolism and efflux, which can lower drug exposure. This may reduce antitumor efficacy.
What this interaction means in plain words
Paclitaxel 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
Induction of CYP3A4 and P-glycoprotein increases paclitaxel clearance.
What to do
Advise patients to stop St John's wort before starting paclitaxel and throughout treatment. Use an alternative for the indication, such as another antidepressant.
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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Other interactions of Paclitaxel
Frequently asked questions
Can I take Paclitaxel with St john's wort?
MediHelp rates the interaction as major. Paclitaxel 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 induces paclitaxel metabolism and efflux, which can lower drug exposure. This may reduce antitumor efficacy.
How serious is the interaction between Paclitaxel 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: Advise patients to stop St John's wort before starting paclitaxel and throughout treatment. Use an alternative for the indication, such as another antidepressant.
What other medicines interact with Paclitaxel?
MediHelp also lists interactions of Paclitaxel with, for example, Adenovirus types 4 and 7 live, Cobicistat, Cyclosporine. The full list is on the Paclitaxel page.
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