Heparin and Warfarin: Drug Interaction Guide
Quick answer: This combination requires caution. Heparin and Warfarin can be used together with adjustments and monitoring.
How Heparin interacts with Warfarin
Heparin potentiates antithrombin-mediated inhibition of clotting factors, while warfarin reduces synthesis of vitamin K-dependent factors. Combined anticoagulant effects increase bleeding risk during bridging.
What you should do
Use overlap only when clinically indicated and monitor bleeding, platelet count, hemoglobin, INR, and relevant heparin assays. Stop heparin once therapeutic anticoagulation criteria are met.
Key facts
Severity
Moderate — caution required
Mechanism
Heparin potentiates antithrombin-mediated inhibition of clotting factors, while warfarin reduces synthesis of vitamin K-...
Action
Use overlap only when clinically indicated and monitor bleeding, platelet count, hemoglobin, INR, and relevant heparin a...
Frequently asked questions
Can I take Heparin and Warfarin together?
With caution. Use overlap only when clinically indicated and monitor bleeding, platelet count, hemoglobin, INR, and relevant heparin assays. Stop heparin once therapeutic anticoagulation criteria are met.
What is the severity of this interaction?
The interaction between Heparin and Warfarin is classified as Moderate — caution required. Heparin potentiates antithrombin-mediated inhibition of clotting factors, while warfarin reduces synthesis of vitamin K-dependent factors. Combined anticoagulant effects increase bleeding risk during bridging.
What should I do if I'm prescribed both?
Use overlap only when clinically indicated and monitor bleeding, platelet count, hemoglobin, INR, and relevant heparin assays. Stop heparin once therapeutic anticoagulation criteria are met. Always consult your prescribing clinician — do not stop or change medications without medical guidance.
Last reviewed: by iMedic Medical Editorial Team. Our editorial process.