Drug interactions
St john's wort + Trazodone
Severity: Major
St john's wort and Trazodone: 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, so combining it with trazodone raises the risk of serotonin syndrome. It also induces CYP3A4 and may lower trazodone concentrations, making the overall effect unpredictable.
What this interaction means in plain words
St john's wort and Trazodone 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 plus CYP3A4 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 for changes in trazodone effect after stopping.
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 Trazodone
- Arsenic trioxide + Trazodone Contraindicated
- Ibutilide + Trazodone Contraindicated
- Isocarboxazid + Trazodone Contraindicated
- Levoketoconazole + Trazodone Contraindicated
- Methylene blue + Trazodone Contraindicated
- Phenelzine + Trazodone Contraindicated
Frequently asked questions
Can I take St john's wort with Trazodone?
MediHelp rates the interaction as major. St john's wort and Trazodone 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, so combining it with trazodone raises the risk of serotonin syndrome. It also induces CYP3A4 and may lower trazodone concentrations, making the overall effect unpredictable.
How serious is the interaction between St john's wort and Trazodone?
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 for changes in trazodone effect after stopping.
What other medicines interact with Trazodone?
MediHelp also lists interactions of Trazodone with, for example, Arsenic trioxide, Ibutilide, Isocarboxazid. The full list is on the Trazodone page.
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