Drug interactions
Ivermectin + St john's wort
Severity: Minor
Ivermectin 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 and may lower ivermectin concentrations. This could reduce antiparasitic efficacy, though specific clinical data are lacking.
What this interaction means in plain words
Ivermectin 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
Hyperforin in St John's wort activates PXR, inducing CYP3A4 and P-glycoprotein and increasing ivermectin clearance.
What to do
No empiric dose change is needed. Assess treatment response and repeat dosing if cure is not achieved.
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 Ivermectin
- Erdafitinib + Ivermectin Moderate
- Ivermectin + Lasmiditan Moderate
- Ivermectin + Quinidine Moderate
- Ivermectin + Rifampin Moderate
- Ivermectin + Sotorasib Moderate
- Ivermectin + Tepotinib Moderate
Frequently asked questions
Can I take Ivermectin with St john's wort?
MediHelp rates the interaction as minor. Ivermectin 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 and may lower ivermectin concentrations. This could reduce antiparasitic efficacy, though specific clinical data are lacking.
How serious is the interaction between Ivermectin 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: No empiric dose change is needed. Assess treatment response and repeat dosing if cure is not achieved.
What other medicines interact with Ivermectin?
MediHelp also lists interactions of Ivermectin with, for example, Erdafitinib, Lasmiditan, Quinidine. The full list is on the Ivermectin page.
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