Drug interactions
Desvenlafaxine + St john's wort
Severity: Major
Desvenlafaxine 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 inhibits serotonin reuptake, and with an SNRI it increases the risk of serotonin syndrome. It also induces CYP3A4, which has a minor role in desvenlafaxine clearance.
What this interaction means in plain words
Desvenlafaxine 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 with hyperforin-related reuptake inhibition, plus CYP3A4 and P-gp induction.
What to do
Avoid the combination and ask patients about herbal use. Stop St John's wort and monitor for serotonin toxicity if it has been taken.
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 Desvenlafaxine
- Desvenlafaxine + Isocarboxazid Contraindicated
- Desvenlafaxine + Methylene blue Contraindicated
- Desvenlafaxine + Phenelzine Contraindicated
- Desvenlafaxine + Rasagiline Contraindicated
- Desvenlafaxine + Safinamide Contraindicated
- Desvenlafaxine + Selegiline Contraindicated
Frequently asked questions
Can I take Desvenlafaxine with St john's wort?
MediHelp rates the interaction as major. Desvenlafaxine 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 inhibits serotonin reuptake, and with an SNRI it increases the risk of serotonin syndrome. It also induces CYP3A4, which has a minor role in desvenlafaxine clearance.
How serious is the interaction between Desvenlafaxine 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 ask patients about herbal use. Stop St John's wort and monitor for serotonin toxicity if it has been taken.
What other medicines interact with Desvenlafaxine?
MediHelp also lists interactions of Desvenlafaxine with, for example, Isocarboxazid, Methylene blue, Phenelzine. The full list is on the Desvenlafaxine page.
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