Indications: DVT, PE, lifelong in pts with heart valves, recurrent MI, strokes, atrial fibrillation
Dosage: Monitor Prothrombin Time (PT), or International Normalized Ratio (INR). Want an INR of 2.0-3.0. Or a PT Ratio of 1.3-1.5
Dosing is q day, and may be started with heparin. Overlap warfarin and heparin days before d/c heparin.
ADR:Hemorrhage! Antidote = phytonadione (Vitamin K)
Also, many drug interactions w/ warfarin (aspirin, vit K, DIET—keep vitamin K constant)