Drug interactions
Loperamide + St john's wort
Severity: Minor
Loperamide and St john's wort: minor 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 CYP3A4 and P-glycoprotein, which may reduce loperamide concentrations. Antidiarrheal efficacy might be lessened.
What this interaction means in plain words
Loperamide and St john's wort have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Why it happens
Induction of CYP3A4 and P-gp increases loperamide clearance and efflux.
What to do
Monitor antidiarrheal response and adjust loperamide only within labeled limits.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Loperamide
Frequently asked questions
Can I take Loperamide with St john's wort?
MediHelp rates the interaction as minor. Loperamide and St john's wort have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. St John's wort induces CYP3A4 and P-glycoprotein, which may reduce loperamide concentrations. Antidiarrheal efficacy might be lessened.
How serious is the interaction between Loperamide and St john's wort?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor antidiarrheal response and adjust loperamide only within labeled limits.
What other medicines interact with Loperamide?
MediHelp also lists interactions of Loperamide with, for example, Amiodarone, Amisulpride, Anagrelide. The full list is on the Loperamide page.
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