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Drug interactions

St john's wort + Tofacitinib

Severity: Major

St john's wort and Tofacitinib: 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 is a CYP3A4 inducer that can lower tofacitinib exposure and reduce efficacy. The extent varies with the herbal product used.

What this interaction means in plain words

St john's wort and Tofacitinib 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.

Evidence level: Moderate

Why it happens

Induction of CYP3A4 increases tofacitinib clearance.

What to do

Advise patients to avoid St John's wort during tofacitinib therapy.

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?

Bring a full list of your medicines, including over-the-counter products, supplements and herbal remedies, to every pharmacy visit.

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Frequently asked questions

Can I take St john's wort with Tofacitinib?

MediHelp rates the interaction as major. St john's wort and Tofacitinib 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 is a CYP3A4 inducer that can lower tofacitinib exposure and reduce efficacy. The extent varies with the herbal product used.

How serious is the interaction between St john's wort and Tofacitinib?

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 avoid St John's wort during tofacitinib therapy.

What other medicines interact with Tofacitinib?

MediHelp also lists interactions of Tofacitinib with, for example, Baricitinib, Cladribine, Upadacitinib. The full list is on the Tofacitinib page.

Full monographs, dosing and an interaction checker in the MediHelp app

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