Drug interactions
Duloxetine + St john's wort
Severity: Major
Duloxetine and St john's wort: major interaction.
Last updated Sources: US FDA label
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 has serotonergic activity and, combined with duloxetine, can contribute to serotonin syndrome. It also induces some metabolic enzymes and may lower duloxetine levels.
What this interaction means in plain words
Duloxetine and St john's wort 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.
Why it happens
Additive serotonin reuptake inhibition, plus enzyme induction by St John's wort.
What to do
Avoid the combination and advise patients to stop St John's wort. Monitor for serotonin toxicity and altered antidepressant response.
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?
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References
Other interactions of Duloxetine
- Duloxetine + Isocarboxazid Contraindicated
- Duloxetine + Linezolid Contraindicated
- Duloxetine + Methylene blue Contraindicated
- Duloxetine + Phenelzine Contraindicated
- Duloxetine + Procarbazine Contraindicated
- Duloxetine + Rasagiline Contraindicated
Frequently asked questions
Can I take Duloxetine with St john's wort?
MediHelp rates the interaction as major. Duloxetine and St john's wort 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 has serotonergic activity and, combined with duloxetine, can contribute to serotonin syndrome. It also induces some metabolic enzymes and may lower duloxetine levels.
How serious is the interaction between Duloxetine and St john's wort?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination and advise patients to stop St John's wort. Monitor for serotonin toxicity and altered antidepressant response.
What other medicines interact with Duloxetine?
MediHelp also lists interactions of Duloxetine with, for example, Isocarboxazid, Linezolid, Methylene blue. The full list is on the Duloxetine page.
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