Drug interactions
Lansoprazole + St john's wort
Severity: Moderate
Lansoprazole and St john's wort: 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
St John's wort induces drug-metabolizing enzymes and can lower lansoprazole exposure. Acid suppression may be weaker, which matters for patients treated for ulcers, erosive esophagitis or H. pylori eradication.
What this interaction means in plain words
Lansoprazole and St john's wort 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.
Why it happens
St John's wort induces CYP2C19 and CYP3A4, increasing the metabolic clearance of lansoprazole.
What to do
Monitor for symptom breakthrough or treatment failure and consider a higher lansoprazole dose if needed. Advise the patient to stop the herbal product if acid control is inadequate.
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 Lansoprazole and St john's wort, 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 14 days on the web. No card needed.
Other interactions of Lansoprazole
- Lansoprazole + Mavacamten Contraindicated
- Lansoprazole + Rilpivirine Contraindicated
- Acalabrutinib + Lansoprazole Major
- Atazanavir + Lansoprazole Major
- Dacomitinib + Lansoprazole Major
- Dasatinib + Lansoprazole Major
Frequently asked questions
Can I take Lansoprazole with St john's wort?
MediHelp rates the interaction as moderate. Lansoprazole and St john's wort 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. St John's wort induces drug-metabolizing enzymes and can lower lansoprazole exposure. Acid suppression may be weaker, which matters for patients treated for ulcers, erosive esophagitis or H. pylori eradication.
How serious is the interaction between Lansoprazole and St john's wort?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for symptom breakthrough or treatment failure and consider a higher lansoprazole dose if needed. Advise the patient to stop the herbal product if acid control is inadequate.
What other medicines interact with Lansoprazole?
MediHelp also lists interactions of Lansoprazole with, for example, Mavacamten, Rilpivirine, Acalabrutinib. The full list is on the Lansoprazole 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.
