Drug interactions
Pemetrexed + Trastuzumab
Severity: Moderate
Pemetrexed 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
Trastuzumab given with myelosuppressive chemotherapy has been associated with a higher incidence of neutropenia. Pemetrexed can itself cause myelosuppression, so additive hematologic toxicity and infection risk are possible, and combination regimens are used in practice.
What this interaction means in plain words
Pemetrexed 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.
Pemetrexed belongs to Oncology; Trastuzumab belongs to Oncology.
Why it happens
Additive hematologic toxicity from pemetrexed myelosuppression and trastuzumab-associated neutropenia.
What to do
Monitor complete blood counts regularly and watch for signs of infection. Ensure folic acid and vitamin B12 supplementation is given with pemetrexed.
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 Pemetrexed
Other interactions of Trastuzumab
Frequently asked questions
Can I take Pemetrexed with Trastuzumab?
MediHelp rates the interaction as moderate. Pemetrexed 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. Trastuzumab given with myelosuppressive chemotherapy has been associated with a higher incidence of neutropenia. Pemetrexed can itself cause myelosuppression, so additive hematologic toxicity and infection risk are possible, and combination regimens are used in practice.
How serious is the interaction between Pemetrexed 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 regularly and watch for signs of infection. Ensure folic acid and vitamin B12 supplementation is given with pemetrexed.
What other medicines interact with Pemetrexed?
MediHelp also lists interactions of Pemetrexed with, for example, Bacitracin, Brexucabtagene autoleucel, Celecoxib. The full list is on the Pemetrexed page.
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