Drug interactions
Paroxetine + St john's wort
Severity: Major
Paroxetine and St john's wort: major 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 has serotonergic activity and combining it with paroxetine can cause serotonin syndrome, with agitation, tremor, hyperthermia, diarrhea and neuromuscular hyperactivity. The risk is greatest after starting or increasing either agent.
What this interaction means in plain words
Paroxetine 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 serotonergic effects from SSRI-mediated serotonin reuptake inhibition and reuptake inhibition by St John's wort constituents.
What to do
Avoid combining them and advise patients to stop St John's wort before or instead of continuing paroxetine. If both were taken, monitor for signs of serotonin toxicity and seek urgent care if they appear.
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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Other interactions of Paroxetine
- Isocarboxazid + Paroxetine Contraindicated
- Methylene blue + Paroxetine Contraindicated
- Paroxetine + Phenelzine Contraindicated
- Paroxetine + Pimozide Contraindicated
- Paroxetine + Procarbazine Contraindicated
- Paroxetine + Selegiline Contraindicated
Frequently asked questions
Can I take Paroxetine with St john's wort?
MediHelp rates the interaction as major. Paroxetine 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 combining it with paroxetine can cause serotonin syndrome, with agitation, tremor, hyperthermia, diarrhea and neuromuscular hyperactivity. The risk is greatest after starting or increasing either agent.
How serious is the interaction between Paroxetine 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 combining them and advise patients to stop St John's wort before or instead of continuing paroxetine. If both were taken, monitor for signs of serotonin toxicity and seek urgent care if they appear.
What other medicines interact with Paroxetine?
MediHelp also lists interactions of Paroxetine with, for example, Isocarboxazid, Methylene blue, Phenelzine. The full list is on the Paroxetine page.
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