Trastuzumab and Doxorubicin: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Doxorubicin
Trastuzumab
No brand names on record
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Increased risk of cardiomyopathy, cardiac dysfunction, arrhythmias, hypertension, disabling cardiac failure and cardiac death
Interaction Deep Dive
Concurrent use of DOXOrubicin (anthracycline) and trastuzumab or trastuzumab biosimilar products increases the incidence and severity of cardiomyopathy. Use of DOXOrubicin should be avoided during trastuzumab therapy and for 7 months following discontinuation of trastuzumab due to trastuzumab's long washout period231. Although no formal drug interaction studies have been done with DOXOrubicin hydrochloride liposome injection, it may interact with drugs known to interact with the conventional formulation of DOXOrubicin 5. Patients who receive anthracycline after stopping trastuzumab may also be at increased risk of cardiac dysfunction. If coadministration is required, monitor cardiac function carefully 23.
Why it happens (mechanism)
Additive or synergistic myocardial damage
Literature reports
2 reports — tap to read
a) When coadministered, concentrations of DOXOrubicin, its major metabolite doxorubicinol, and trastuzumab were not altered when used as combination therapy in clinical trials 4.
b) Although no formal drug interaction studies have been done with DOXOrubicin hydrochloride liposome injection, it may interact with drugs known to interact with the conventional formulation of DOXOrubicin 5.
Common questions
Can I take Trastuzumab and Doxorubicin together?
Increased risk of cardiomyopathy, cardiac dysfunction, arrhythmias, hypertension, disabling cardiac failure and cardiac death Always confirm with your pharmacist or prescriber before making any change.
How serious is the Trastuzumab and Doxorubicin interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Trastuzumab or Doxorubicin need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (5)
- Product Information: Doxorubicin hydrochloride intravenous injection, doxorubicin hydrochloride intravenous injection. Pfizer Labs (per manufacturer), New York, NY, 2020. DailyMed
- Product Information: HERZUMA(R) intravenous injection, trastuzumab-pkrb intravenous injection. Teva Pharmaceuticals USA Inc (per FDA), North Wales, PA, 2019. DailyMed
- Product Information: HERCESSI(TM) intravenous injection, trastuzumab-strf intravenous injection. Accord BioPharma Inc. (Per FDA), Raleigh, NC, 2024. DailyMed
- Product Information: HERZUMA(R) intravenous injection, trastuzumab-pkrb intravenous injection. Teva Pharmaceuticals, Inc (per FDA), North Wales, PA, 2018. DailyMed
- Product Information: DOXIL(R) intravenous injection, doxorubicin HCl liposome intravenous injection. Janssen Products, LP (per FDA), Horsham, PA, 2015. DailyMed
Keep reading about Doxorubicin
Keep reading about Trastuzumab
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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