Drug interactions
Methotrexate + Trastuzumab deruxtecan
Severity: Moderate
Methotrexate and Trastuzumab deruxtecan: 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
Trastuzumab deruxtecan causes neutropenia and other cytopenias, and with methotrexate these effects may be compounded. Infection risk may rise.
What this interaction means in plain words
Methotrexate and Trastuzumab deruxtecan 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.
Methotrexate belongs to Oncology; Trastuzumab deruxtecan belongs to Oncology.
Why it happens
Additive myelosuppression and immunosuppression from the topoisomerase I inhibitor payload and the antimetabolite.
What to do
Monitor complete blood counts before each dose and for signs of infection. Delay or reduce doses for significant neutropenia.
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
Other interactions of Trastuzumab deruxtecan
Frequently asked questions
Can I take Methotrexate with Trastuzumab deruxtecan?
MediHelp rates the interaction as moderate. Methotrexate and Trastuzumab deruxtecan 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. Trastuzumab deruxtecan causes neutropenia and other cytopenias, and with methotrexate these effects may be compounded. Infection risk may rise.
How serious is the interaction between Methotrexate and Trastuzumab deruxtecan?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor complete blood counts before each dose and for signs of infection. Delay or reduce doses for significant neutropenia.
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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