Drug interactions
Fondaparinux + Mestranol
Severity: Major
Fondaparinux and Mestranol: major 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
Mestranol, an estrogen used in some oral contraceptives, increases thrombosis risk and works against fondaparinux therapy in patients with clots or high thrombotic risk.
What this interaction means in plain words
Fondaparinux and Mestranol 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.
Why it happens
Pharmacodynamic opposition: estrogen-related increases in clotting factors versus factor Xa inhibition.
What to do
Avoid estrogen-containing contraception during active VTE; use a non-hormonal or progestin-only method. Review the need for estrogen therapy.
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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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 Mestranol?
MediHelp rates the interaction as major. Fondaparinux and Mestranol 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. Mestranol, an estrogen used in some oral contraceptives, increases thrombosis risk and works against fondaparinux therapy in patients with clots or high thrombotic risk.
How serious is the interaction between Fondaparinux and Mestranol?
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 estrogen-containing contraception during active VTE; use a non-hormonal or progestin-only method. Review the need for estrogen therapy.
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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