Drug interactions
Methotrexate + Willow bark
Severity: Moderate
Methotrexate and Willow bark: 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
Willow bark contains salicin, which is converted to salicylate and may compete with methotrexate for renal tubular secretion. This may raise methotrexate levels and increase its toxicity, especially with higher methotrexate doses or reduced renal function.
What this interaction means in plain words
Methotrexate and Willow bark 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
Salicylate competes with methotrexate for renal tubular secretion and may displace it from protein binding.
What to do
Avoid willow bark with high-dose methotrexate. With low-dose therapy, monitor blood counts and renal function and watch for mucositis or cytopenias.
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 Methotrexate
- Acitretin + Methotrexate Contraindicated
- Adenovirus types 4 and 7 live + Methotrexate Contraindicated
- Influenza virus vaccine quadrivalent intranasal + Methotrexate Contraindicated
- Ketorolac + Methotrexate Contraindicated
- Measles mumps and rubella vaccine live + Methotrexate Contraindicated
- Measles mumps and rubella vaccine + Methotrexate Contraindicated
Frequently asked questions
Can I take Methotrexate with Willow bark?
MediHelp rates the interaction as moderate. Methotrexate and Willow bark 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. Willow bark contains salicin, which is converted to salicylate and may compete with methotrexate for renal tubular secretion. This may raise methotrexate levels and increase its toxicity, especially with higher methotrexate doses or reduced renal function.
How serious is the interaction between Methotrexate and Willow bark?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid willow bark with high-dose methotrexate. With low-dose therapy, monitor blood counts and renal function and watch for mucositis or cytopenias.
What other medicines interact with Methotrexate?
MediHelp also lists interactions of Methotrexate with, for example, Acitretin, Adenovirus types 4 and 7 live, Influenza virus vaccine quadrivalent intranasal. The full list is on the Methotrexate page.
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