1. Risk factors for bleeding on heparin:

1. Surgery, trauma, or stroke within the previous 14 days.

2. History of peptic ulcer disease, GI bleeding or GU bleeding.

3. Platelet count < 150,000.

4. Miscellaneous factors such as hepatic failure, uremia, or brain metastases or presence of underlying coagulopathy.

5. Age > 70 years.

6. Concomitant antithrombotic therapy (e.g. thrombolytics, antiplatelet therapy)

7. Recent or anticipated central or arterial catheterization.

2. Duration of heparin: For patients who require concomitant heparin and warfarin therapy, a minimum of 5 days overlap is required.

3. For dosing of the low molecular weight heparins [e.g., Enoxaparin (Lovenox®)], especially in the setting of renal compromise, please contact Comprehensive Hemostasis and Antithrombotic Service (CHAS) pager 719-4023 or Hematology consultation service, pager 719-4276.

4. Warfarin (Coumadin®) dosing algorithm:

Any increase in INR of greater than 0.3-0.4 units per day should result in a dose reduction.

NOTE: These guidelines are recommendations. They are not intended to replace an individual clinician's judgment.

5. Considerations for oral anticoagulation with warfarin:

1. Many drugs may interfere with the anticoagulant effect of warfarin.

   • The addition or deletion of any medication(s) may alter this effect.

   • For a listing of interfering medications, contact CHAS.

2. Additional factors that may influence warfarin response include coagulopathy caused by disorders such as CHF, hepatic disease, nutritional vitamin K deficiency, and febrile illnesses.

3. Warfarin should not be administered during pregnancy.

4. PT/INR should be ordered daily.

5. Therapeutic range for warfarin:

   1. INR 2.5-3.5 for most mechanical prosthetic valves or recurrent systemic embolism

   2. INR 2.0-3.0 for most other indications.

6. Follow-up appointments with the UCSF Anticoagulation Clinic may be coordinated with the Comprehensive Hemostasis and Antithrombotic Service (CHAS).

7. For patients being treated for unstable angina, NSTEMI or STEMI, please use ANTITHROMBOTIC ORDER FORM #734-038.

8. For any anticoagulation education tools, contact CHAS.