Factors in INR Elevation Requiring Injection of Vitamin K in Outpatients Prescribed Warfarin

Abstract

A very important instruction given to patients prescribed warfarin potassium(Wf)is to seek urgent medical help if bleeding occurs.However,it is a good idea for patients to seek help and ensure that they are being adequately treated with vitamin K(VK)injection before bleeding actually occurs.We retrospectively investigated the causes of enhanced international normalized ratio(INR)in outpatients prescribed Wf and using VK injection from 2000-2004.Owing to a higher INR,nine outpatients(mean age : 72.3)were injected with VK in this period.Two of them were injected with VK at the first consultation after hospitalization during which Wf therapy had been started,and the remaining 7 had appetite loss due to various causes,exacerbation of their underlying disease,overwork or drinking.Therefore,patients prescribed Wf should be instructed to seek immediate medical help when they have appetite loss of various causes before actual bleeding occurs and pay attention to bleeding,especially soon after the dose of Wf is determined.