• Assess patient taking anticoagulants for signs of bleeding and hemorrhage (bleeding gums; nosebleed; unusual bruising; tarry, black stools; hematuria; fall in hematocrit or blood pressure; guaiac-positive stools; urine; or NG aspirate).

• Assess patient for evidence of additional or increased thrombosis. Symptoms will depend on area of involvement.

• Lab Test Considerations: Monitor prothrombin time (PT) or international normalized ratio (INR) with warfarin therapy, activated partial thromboplastin time (aPTT) with full-dose heparin therapy and hematocrit, and other clotting factors frequently during therapy.

• Monitor bleeding time throughout antiplatelet therapy. Prolonged bleeding time, which is time and dose dependent, is expected.

• Toxicity and Overdose: If overdose occurs or anticoagulation needs to be immediately reversed, the antidote for heparins is protamine sulfate; for warfarin, the antidote is vitamin K (phytonadione [AquaMEPHYTON]). Administration of whole blood or plasma may also be required in severe bleeding due to warfarin because of the delayed onset of vitamin K.