Anaphylaxis after low dose intravenous vitamin K.

Over-anticoagulation from warfarin is a common occurrence, and these patients are often referred to the Emergency Department for further treatment. Unfortunately, there is little guidance in the Emergency Medicine literature for the management of such patients. The American College of Chest Physicians (ACCP) issued guidelines in 1998 that address the use of vitamin K for patients with over-anticoagulation. However, there is still debate as to the optimal dose and route of vitamin K administration. This case report describes a patient who was treated with intravenous vitamin K within the scope of these guidelines at a very low dose (1 mg) and had a fatal anaphylactic reaction. This article will further discuss this patient, the 1998 ACCP guidelines, and the data supporting the alternative of subcutaneously administered vitamin K for patients with over-anticoagulation with no active bleeding.