Vitamin K administration – Routes comparison

Let’s start with a patient case.  A patient is admitted to the hospital with a CHF exacerbation.  They are taking warfarin for atrial fibrillation and their coagulation panel reveals an INR of 8.  What are our options for administering vitamin K and some of the nuances for each route of administration?

Scenarios similar to this are common occurrences in the internal medicine setting as heart failure is an independent risk factor for overanticoagulation.  The decision whether or not to use vitamin K should be based on several factors which will not be addressed now.

Vitamin K can be administered by the oral, intravenous, intramuscular, or subcutaneous routes.  Vitamin K is a fat-soluble vitamin of which there are two types; one we find in green vegetables (and lots of other foods) and the other is synthesized by intestinal bacteria.  The vitamin K that we give for therapeutic use is the former, phytonadione.¹