Drug interactions
Antithrombin iii + Fondaparinux
Severity: Moderate
Antithrombin iii and Fondaparinux: 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
Antithrombin III concentrate boosts the plasma activity of the very cofactor that fondaparinux needs, so anticoagulant effect can be amplified. This raises the likelihood of bleeding, especially in surgical or high-risk patients.
What this interaction means in plain words
Antithrombin iii and Fondaparinux 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
Fondaparinux acts by binding antithrombin to inhibit factor Xa, so supplemental antithrombin enhances this pharmacodynamic effect.
What to do
Monitor for bleeding and anti-Xa activity if the combination is needed, for example in antithrombin deficiency. Reassess the fondaparinux dose while antithrombin is being replaced.
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 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 Antithrombin iii with Fondaparinux?
MediHelp rates the interaction as moderate. Antithrombin iii and Fondaparinux 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. Antithrombin III concentrate boosts the plasma activity of the very cofactor that fondaparinux needs, so anticoagulant effect can be amplified. This raises the likelihood of bleeding, especially in surgical or high-risk patients.
How serious is the interaction between Antithrombin iii and Fondaparinux?
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 for bleeding and anti-Xa activity if the combination is needed, for example in antithrombin deficiency. Reassess the fondaparinux dose while antithrombin is being replaced.
What other medicines interact with Fondaparinux?
MediHelp also lists interactions of Fondaparinux with, for example, Defibrotide, Ketorolac, Abciximab. The full list is on the Fondaparinux page.
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