Why Is Heparin Administered Concurrently with Warfarin?

Heparin is administered in combination with warfarin the first week, because haparin potentiates the inhibitory effect of antithrombin, in order to protect the patient against the increased risk of thrombosis, induced by the effect of warfarin on protein C.

Can you use warfarin and heparin together?

Interactions between your drugs

Using heparin together with warfarin can cause you to bleed more easily. You may need a dose adjustment in addition to testing of your prothrombin time or International Normalized Ratio (INR).

Can warfarin be given without heparin?

There has been some concern with starting warfarin without concomitant heparin. This is due to the fact that two vitamin K dependent factors, protein C and protein S, are natural anticoagulants and they have very short half-lives of about 7 hours.