Drug interactions
St john's wort + Ziprasidone
Severity: Moderate
St john's wort and Ziprasidone: 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 induces CYP3A4 and may lower ziprasidone concentrations, potentially reducing antipsychotic efficacy. Because ziprasidone is only partly cleared by CYP3A4, the effect is likely modest. Serotonergic effects of the herb may also add to the pharmacodynamic activity of ziprasidone.
What this interaction means in plain words
St john's wort and Ziprasidone 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
Induction of CYP3A4 (and P-glycoprotein) by hyperforin increases ziprasidone clearance.
What to do
Advise patients to avoid St John's wort and monitor for relapse of psychiatric symptoms. If the herb is stopped, reassess the ziprasidone dose.
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 Ziprasidone
- Amiodarone + Ziprasidone Contraindicated
- Amitriptyline + Ziprasidone Contraindicated
- Arsenic trioxide + Ziprasidone Contraindicated
- Bedaquiline + Ziprasidone Contraindicated
- Chloroquine + Ziprasidone Contraindicated
- Citalopram + Ziprasidone Contraindicated
Frequently asked questions
Can I take St john's wort with Ziprasidone?
MediHelp rates the interaction as moderate. St john's wort and Ziprasidone 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 induces CYP3A4 and may lower ziprasidone concentrations, potentially reducing antipsychotic efficacy. Because ziprasidone is only partly cleared by CYP3A4, the effect is likely modest. Serotonergic effects of the herb may also add to the pharmacodynamic activity of ziprasidone.
How serious is the interaction between St john's wort and Ziprasidone?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Advise patients to avoid St John's wort and monitor for relapse of psychiatric symptoms. If the herb is stopped, reassess the ziprasidone dose.
What other medicines interact with Ziprasidone?
MediHelp also lists interactions of Ziprasidone with, for example, Amiodarone, Amitriptyline, Arsenic trioxide. The full list is on the Ziprasidone page.
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