Drug interactions
Fondaparinux + Heparin
Severity: Major
Fondaparinux and Heparin: major interaction.
Last updated Sources: EMA SmPC
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
Both agents act via antithrombin, so combined use adds to anticoagulant effect and bleeding risk. Duplicate therapy is rarely justified, though heparin may be used briefly during procedures such as PCI.
What this interaction means in plain words
Fondaparinux and Heparin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Fondaparinux belongs to Cardiovascular; Heparin belongs to Cardiovascular.
Why it happens
Additive antithrombin-mediated inhibition of factor Xa (and IIa with heparin).
What to do
Avoid routine co-administration; when switching, start the new drug at the time the next dose of the other is due. Monitor for bleeding and hemoglobin.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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References
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 Fondaparinux
- Defibrotide + Fondaparinux Contraindicated
- Fondaparinux + Ketorolac Contraindicated
- Abciximab + Fondaparinux Major
- Aceclofenac + Fondaparinux Major
- Acetylsalicylic acid + Fondaparinux Major
- Alteplase + Fondaparinux Major
Frequently asked questions
Can I take Fondaparinux with Heparin?
MediHelp rates the interaction as major. Fondaparinux and Heparin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Both agents act via antithrombin, so combined use adds to anticoagulant effect and bleeding risk. Duplicate therapy is rarely justified, though heparin may be used briefly during procedures such as PCI.
How serious is the interaction between Fondaparinux and Heparin?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid routine co-administration; when switching, start the new drug at the time the next dose of the other is due. Monitor for bleeding and hemoglobin.
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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