Drug interactions
Dalteparin + Heparin
Severity: Major
Dalteparin and Heparin: 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
Unfractionated heparin and a low molecular weight heparin both act through antithrombin, so combining them duplicates therapy and increases bleeding risk. There is rarely a reason to give both at therapeutic doses.
What this interaction means in plain words
Dalteparin 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.
Dalteparin belongs to Cardiovascular; Heparin belongs to Cardiovascular.
Why it happens
Additive anti-factor Xa and anti-IIa activity via antithrombin potentiation.
What to do
Avoid concurrent therapeutic dosing; give one heparin product at a time and start the next at the time the following dose is due. Monitor for bleeding and platelet counts.
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 Heparin
- Defibrotide + Heparin Contraindicated
- Heparin + Ketorolac Contraindicated
- Heparin + Oritavancin Contraindicated
- Acemetacin + Heparin Major
- Acetylsalicylic acid + Heparin Major
- Alteplase + Heparin Major
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 Heparin?
MediHelp rates the interaction as major. Dalteparin 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. Unfractionated heparin and a low molecular weight heparin both act through antithrombin, so combining them duplicates therapy and increases bleeding risk. There is rarely a reason to give both at therapeutic doses.
How serious is the interaction between Dalteparin 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 concurrent therapeutic dosing; give one heparin product at a time and start the next at the time the following dose is due. Monitor for bleeding and platelet counts.
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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