Drug interactions
Amiodarone + St john's wort
Severity: Major
Amiodarone 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 induces drug-metabolizing enzymes and transporters and may lower amiodarone concentrations, risking loss of arrhythmia control. The effect fades slowly after the herb is stopped, which can lead to fluctuating amiodarone levels.
What this interaction means in plain words
Amiodarone 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
Induction of CYP3A4 and P-gp by hyperforin increases amiodarone clearance.
What to do
Advise patients to avoid St John's wort. If it was already taken, monitor rhythm and ECG and reassess the amiodarone dose when it is stopped.
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 Amiodarone
- Amiodarone + Amisulpride Contraindicated
- Amiodarone + Arsenic trioxide Contraindicated
- Amiodarone + Dofetilide Contraindicated
- Amiodarone + Dronedarone Contraindicated
- Amiodarone + Droperidol Contraindicated
- Amiodarone + Eliglustat Contraindicated
Frequently asked questions
Can I take Amiodarone with St john's wort?
MediHelp rates the interaction as major. Amiodarone 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 induces drug-metabolizing enzymes and transporters and may lower amiodarone concentrations, risking loss of arrhythmia control. The effect fades slowly after the herb is stopped, which can lead to fluctuating amiodarone levels.
How serious is the interaction between Amiodarone 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: Advise patients to avoid St John's wort. If it was already taken, monitor rhythm and ECG and reassess the amiodarone dose when it is stopped.
What other medicines interact with Amiodarone?
MediHelp also lists interactions of Amiodarone with, for example, Amisulpride, Arsenic trioxide, Dofetilide. The full list is on the Amiodarone page.
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