Drug interactions
Azathioprine + Trastuzumab deruxtecan
Severity: Major
Azathioprine and Trastuzumab deruxtecan: 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
Trastuzumab deruxtecan commonly causes neutropenia, and azathioprine also suppresses marrow and immune function. Together they may increase the risk of severe neutropenia and infection.
What this interaction means in plain words
Azathioprine and Trastuzumab deruxtecan 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.
Azathioprine belongs to Gastrointestinal Tract; Trastuzumab deruxtecan belongs to Oncology.
Why it happens
Additive myelosuppression and immunosuppression from the cytotoxic topoisomerase I inhibitor payload and azathioprine's antimetabolite effect.
What to do
Monitor complete blood counts before each trastuzumab deruxtecan dose and watch for fever or infection. Consider reducing or stopping azathioprine if neutropenia develops.
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 Azathioprine
- Adenovirus types 4 and 7 live + Azathioprine Contraindicated
- Azathioprine + Bcg vaccine live Contraindicated
- Azathioprine + Febuxostat Contraindicated
- Azathioprine + Influenza virus vaccine quadrivalent intranasal Contraindicated
- Azathioprine + Measles mumps and rubella vaccine Contraindicated
- Azathioprine + Measles mumps and rubella vaccine live Contraindicated
Other interactions of Trastuzumab deruxtecan
Frequently asked questions
Can I take Azathioprine with Trastuzumab deruxtecan?
MediHelp rates the interaction as major. Azathioprine and Trastuzumab deruxtecan 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. Trastuzumab deruxtecan commonly causes neutropenia, and azathioprine also suppresses marrow and immune function. Together they may increase the risk of severe neutropenia and infection.
How serious is the interaction between Azathioprine and Trastuzumab deruxtecan?
MediHelp rates it major, 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 trastuzumab deruxtecan dose and watch for fever or infection. Consider reducing or stopping azathioprine if neutropenia develops.
What other medicines interact with Azathioprine?
MediHelp also lists interactions of Azathioprine with, for example, Adenovirus types 4 and 7 live, Bcg vaccine live, Febuxostat. The full list is on the Azathioprine page.
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