Drug interactions
Obinutuzumab + Trastuzumab
Severity: Moderate
Obinutuzumab and Trastuzumab: 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
Obinutuzumab causes profound B-cell depletion and neutropenia, and trastuzumab has been associated with increased neutropenia when given with myelosuppressive therapy. Used together, for example in oncology regimens, the risk of infection and febrile neutropenia may be higher than with either drug alone.
What this interaction means in plain words
Obinutuzumab and Trastuzumab 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.
Obinutuzumab belongs to Oncology; Trastuzumab belongs to Oncology.
Why it happens
Additive myelosuppressive and immunosuppressive effects; the contribution of trastuzumab is modest and not fully characterised.
What to do
Monitor complete blood counts, especially neutrophils, and watch for signs of infection during combined treatment. Use growth factor support or antimicrobial prophylaxis according to local protocols.
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 Trastuzumab
Other interactions of Obinutuzumab
Frequently asked questions
Can I take Obinutuzumab with Trastuzumab?
MediHelp rates the interaction as moderate. Obinutuzumab and Trastuzumab 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. Obinutuzumab causes profound B-cell depletion and neutropenia, and trastuzumab has been associated with increased neutropenia when given with myelosuppressive therapy. Used together, for example in oncology regimens, the risk of infection and febrile neutropenia may be higher than with either drug alone.
How serious is the interaction between Obinutuzumab and Trastuzumab?
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, especially neutrophils, and watch for signs of infection during combined treatment. Use growth factor support or antimicrobial prophylaxis according to local protocols.
What other medicines interact with Trastuzumab?
MediHelp also lists interactions of Trastuzumab with, for example, Daunorubicin, Doxorubicin liposomal, Doxorubicin. The full list is on the Trastuzumab page.
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