Drug interactions
Dalteparin + Mestranol
Severity: Major
Dalteparin 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 is the ethinyl estradiol-like prodrug found in some oral contraceptives and increases the risk of thrombosis. In patients needing dalteparin for thrombosis, this undermines the anticoagulant benefit.
What this interaction means in plain words
Dalteparin 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-driven increases in clotting factors versus heparin anticoagulation.
What to do
Avoid estrogen-containing contraception during active VTE or high thrombotic risk; use a non-hormonal or progestin-only method. Review the need for continued 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 Dalteparin
- Dalteparin + Defibrotide Contraindicated
- Dalteparin + Ketorolac Contraindicated
- Dalteparin + Mifepristone Contraindicated
- Abciximab + Dalteparin Major
- Acalabrutinib + Dalteparin Major
- Aceclofenac + Dalteparin Major
Frequently asked questions
Can I take Dalteparin with Mestranol?
MediHelp rates the interaction as major. Dalteparin 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 is the ethinyl estradiol-like prodrug found in some oral contraceptives and increases the risk of thrombosis. In patients needing dalteparin for thrombosis, this undermines the anticoagulant benefit.
How serious is the interaction between Dalteparin 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 or high thrombotic risk; use a non-hormonal or progestin-only method. Review the need for continued estrogen therapy.
What other medicines interact with Dalteparin?
MediHelp also lists interactions of Dalteparin with, for example, Defibrotide, Ketorolac, Mifepristone. The full list is on the Dalteparin page.
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