Drug interactions
Fluorouracil + Influenza a vaccine
Severity: Moderate
Fluorouracil and Influenza a vaccine: 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
Cytotoxic chemotherapy such as fluorouracil suppresses bone marrow and immune function, which can blunt the antibody response to influenza vaccines including H5N1. Patients may therefore be less protected despite vaccination.
What this interaction means in plain words
Fluorouracil and Influenza a vaccine 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.
Why it happens
Chemotherapy-induced myelosuppression and immunosuppression reduce vaccine immunogenicity.
What to do
Where possible, vaccinate before starting chemotherapy or between cycles when counts have recovered. Do not rely on vaccine response alone and maintain other protective measures.
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 Fluorouracil
Frequently asked questions
Can I take Fluorouracil with Influenza a vaccine?
MediHelp rates the interaction as moderate. Fluorouracil and Influenza a vaccine 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. Cytotoxic chemotherapy such as fluorouracil suppresses bone marrow and immune function, which can blunt the antibody response to influenza vaccines including H5N1. Patients may therefore be less protected despite vaccination.
How serious is the interaction between Fluorouracil and Influenza a vaccine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Where possible, vaccinate before starting chemotherapy or between cycles when counts have recovered. Do not rely on vaccine response alone and maintain other protective measures.
What other medicines interact with Fluorouracil?
MediHelp also lists interactions of Fluorouracil with, for example, Adenovirus types 4 and 7 live, Axicabtagene ciloleucel, Belatacept. The full list is on the Fluorouracil page.
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