Drug interactions
Fluorouracil + Heparin
Severity: Moderate
Fluorouracil and Heparin: 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
Fluorouracil causes myelosuppression including thrombocytopenia, which increases bleeding risk during heparin therapy. The risk is greatest when platelet counts are low.
What this interaction means in plain words
Fluorouracil and Heparin 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.
Fluorouracil belongs to Oncology; Heparin belongs to Cardiovascular.
Why it happens
Additive bleeding risk from chemotherapy-induced thrombocytopenia combined with heparin anticoagulation.
What to do
Monitor platelet counts regularly and for bleeding. Reduce or hold heparin when platelets fall below accepted safety thresholds.
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 Heparin
- Defibrotide + Heparin Contraindicated
- Heparin + Ketorolac Contraindicated
- Heparin + Oritavancin Contraindicated
- Acemetacin + Heparin Major
- Acetylsalicylic acid + Heparin Major
- Alteplase + Heparin Major
Other interactions of Fluorouracil
Frequently asked questions
Can I take Fluorouracil with Heparin?
MediHelp rates the interaction as moderate. Fluorouracil and Heparin 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. Fluorouracil causes myelosuppression including thrombocytopenia, which increases bleeding risk during heparin therapy. The risk is greatest when platelet counts are low.
How serious is the interaction between Fluorouracil and Heparin?
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 platelet counts regularly and for bleeding. Reduce or hold heparin when platelets fall below accepted safety thresholds.
What other medicines interact with Heparin?
MediHelp also lists interactions of Heparin with, for example, Defibrotide, Ketorolac, Oritavancin. The full list is on the Heparin page.
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