Drug interactions
Conjugated estrogens + Dalteparin
Severity: Major
Conjugated estrogens and Dalteparin: 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
Conjugated estrogens raise the risk of venous thromboembolism. In a patient requiring dalteparin for a thrombotic condition, estrogen therapy works against the goal of anticoagulation.
What this interaction means in plain words
Conjugated estrogens and Dalteparin 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: estrogens increase procoagulant factors and reduce natural anticoagulants.
What to do
Avoid estrogen therapy in patients with active thrombosis or a high VTE risk and use a non-hormonal option for symptoms. If it must be used, review the indication and VTE risk periodically.
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 Conjugated estrogens with Dalteparin?
MediHelp rates the interaction as major. Conjugated estrogens and Dalteparin 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. Conjugated estrogens raise the risk of venous thromboembolism. In a patient requiring dalteparin for a thrombotic condition, estrogen therapy works against the goal of anticoagulation.
How serious is the interaction between Conjugated estrogens and Dalteparin?
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 therapy in patients with active thrombosis or a high VTE risk and use a non-hormonal option for symptoms. If it must be used, review the indication and VTE risk periodically.
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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