Warfarin - INR Goals, Initial Dosing and Bridging



Mechanical Mitral Valve Replacement 2.5-3.5 

Other Valve Replacement 2-3 

VTE Treatment/Prophylaxis 2-3 

Atrial Fibrillation 2-3 



Here's a review of some key information for appropriate warfarin dosing in ambulatory care. Basically the INR goal is always 2-3 unless it's specifically a mechanical mitral valve replacement. In ambulatory care, we generally start patients on warfarin 5 mg daily, but may do a lower dose of 2.5 mg daily if patients are elderly or have high bleeding risks. Alternatively, sometimes a loading dose of 10 mg on the first two days is a better strategy if trying to get to therapeutic range quickly. If the patient has an active clot (i.e. VTE treatment), bridging is needed because warfarin is pro-coagulant in the first 5 days due to depletion of natural anticoagulants Protein C & S. Bridging is usually enoxaparin, at a dose of 1 mg/kg Q12H for at least 5 days and until INR is therapeutic twice.



Jarred Prudencio, PharmD - https://www.instagram.com/ambcarerx



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