Dextran and Heparin Injection: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Heparin Injection
Dextran
No brand names on record
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Increased risk of bleeding
Interaction Deep Dive
The additional effects of dextran 70 (reduced RBC viscosity, prevention of erythrocyte agglutination, impairment of platelet function, altered transformation of fibrinogen to fibrin, and inhibition of prostaglandin E) coupled with heparin anticoagulant therapy will increase the potential for severe bleeding12.
Why it happens (mechanism)
Additive anticoagulant effects
Common questions
Can I take Dextran and Heparin Injection together?
Increased risk of bleeding Always confirm with your pharmacist or prescriber before making any change.
How serious is the Dextran and Heparin Injection interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "delayed". Effects tend to build up gradually over days to weeks.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Dextran or Heparin Injection need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (2)
- Morrison ND, Stephenson CB, Maclean D, et al: Deep vein thrombosis after femoropopliteal bypass grafting with observations on the incidence of complications following the use of dextran 70. N Z Med J 1976; 84:233-236.
- Schondorf TH & Weber U: Prevention of deep vein thrombosis in orthopedic surgery with the combination of low dose heparin plus either dihydroergotamine or dextran. Scand J Haematol Suppl 1980; 36:126-140. PubMed
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