Drug interactions
Ifosfamide + St john's wort
Severity: Moderate
Ifosfamide and St john's wort: 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 is a potent inducer of CYP3A4 and can increase ifosfamide conversion to active metabolites and to neurotoxic and nephrotoxic chloroacetaldehyde. This may increase toxicity and make exposure unpredictable.
What this interaction means in plain words
Ifosfamide and St john's wort 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 (via PXR) increases ifosfamide metabolism.
What to do
Advise patients to stop St John's wort before and during ifosfamide chemotherapy. Monitor for neurotoxicity, nephrotoxicity and myelosuppression if exposure occurs.
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 Ifosfamide
- Adenovirus types 4 and 7 live + Ifosfamide Contraindicated
- Ifosfamide + Measles mumps and rubella vaccine Contraindicated
- Ifosfamide + Measles mumps and rubella vaccine live Contraindicated
- Ifosfamide + Measles mumps rubella and varicella vaccine live Contraindicated
- Ifosfamide + Measles vaccine Contraindicated
- Ifosfamide + Rotavirus oral vaccine live Contraindicated
Frequently asked questions
Can I take Ifosfamide with St john's wort?
MediHelp rates the interaction as moderate. Ifosfamide and St john's wort 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 is a potent inducer of CYP3A4 and can increase ifosfamide conversion to active metabolites and to neurotoxic and nephrotoxic chloroacetaldehyde. This may increase toxicity and make exposure unpredictable.
How serious is the interaction between Ifosfamide and St john's wort?
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 stop St John's wort before and during ifosfamide chemotherapy. Monitor for neurotoxicity, nephrotoxicity and myelosuppression if exposure occurs.
What other medicines interact with Ifosfamide?
MediHelp also lists interactions of Ifosfamide with, for example, Adenovirus types 4 and 7 live, Measles mumps and rubella vaccine, Measles mumps and rubella vaccine live. The full list is on the Ifosfamide page.
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