Inhibits synthesis of vitamin K dependent factors ( II, VII, IX, X, protein C + S) by inhibiting Vitamin K epoxide reductase
Goal INR is 2.0-3.0 (2.5-3.5 in patients with mechanical valves)
Complications:
Warfarin-induced necrosis (associated with protein C deficiency)
Serious bleeding (rapid reversal of anticoagulation with FFP)
Retroperitoneal hematoma
Side Effects:
Teratogenic (small size allows placental crossing)
False positive test for protein S deficiency
Notes:
Decrease warfarin efficacy
Foods rich in Vitamin K (eg. dark green veggies)
Increase warfarin activity
ETOH
Vitamin E
Ginko bilboa, ginseng, St. John's wort
Several ABX
