Drug interactions
Dapsone + St john's wort
Severity: Moderate
Dapsone 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 may reduce dapsone concentrations, risking loss of efficacy in infection treatment or prophylaxis.
What this interaction means in plain words
Dapsone 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 CYP3A4 and P-glycoprotein, increasing dapsone clearance.
What to do
Avoid the combination where possible; if used, monitor clinical response.
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?
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Other interactions of Dapsone
- Bcg vaccine live + Dapsone Major
- Dapsone + Primaquine Major
- Apalutamide + Dapsone Moderate
- Belzutifan + Dapsone Moderate
- Bosentan + Dapsone Moderate
- Bupivacaine implant + Dapsone Moderate
Frequently asked questions
Can I take Dapsone with St john's wort?
MediHelp rates the interaction as moderate. Dapsone 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 may reduce dapsone concentrations, risking loss of efficacy in infection treatment or prophylaxis.
How serious is the interaction between Dapsone 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: Avoid the combination where possible; if used, monitor clinical response.
What other medicines interact with Dapsone?
MediHelp also lists interactions of Dapsone with, for example, Bcg vaccine live, Primaquine, Apalutamide. The full list is on the Dapsone page.
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