The choice of approach should depend upon the perceived risk of bleeding, extent of bleed, site of bleed, INR level (and trend in INR), comorbidities (including indication for anticoagulation) and risk of thromboembolism. There is general consensus regarding holding a dose of warfarin in these scenarios but the choice to administer vitamin K has been debated. But how do we manage the patient who has a moderately elevated INR but only a minor bleed? In the setting of minor bleeding (such as intermittent epistaxis), the goal is restore the INR to target range, without leading to subtherapeutic anticoagulation, thus introducing the risk of thrombosis. The management of life-threatening bleeding is clear and requires aggressive therapy. In the setting of life-threatening bleed, guidelines dictate our therapeutic approach, which involves holding warfarin and administering 4-factor PCC and intravenous vitamin K (10mg slow infusion over 20-60 minutes)1.

In addition to your excellent teaching points, I have outlined some additional considerations below. Yet, the choice of when to administer this antidote (and weaknesses of said antidote), along with other therapies including prothrombin complex concentrates (PCCs) and fresh frozen plasma, are not straightforward and depend upon a number of factors. Fortunately, warfarin does have an antidote in vitamin K.

Warfarin is notorious for being one of the most difficult medications to manage based on narrow therapeutic index, variable dose response, clinically significant diet- and drug- drug interactions, delayed onset and offset of action and the need for frequent monitoring. This is an excellent post on the management of supratherapeutic INR in patients taking vitamin K antagonist therapy – and as you described, there is not a one-size-fits-all approach.

Antidote coumadin