AKA vitamin K antagonist VKA, anticoagulant, "group of substances that reduce blood clotting by reducing the action of vitamin K. The term "vitamin K antagonist" is technically a misnomer, as the drugs do not directly antagonise the action of vitamin K in the pharmacological sense, but rather the recycling of vitamin K." Source: [https://en.wikipedia.org/wiki/Vitamin_K_antagonist]