The Distribution of Warfarin (Coumadin) in the Rat

Abstract

SummaryIt has been demonstrated that Coumadin, warfarin sodium, following intravenous administration in male albino rats was distributed quickly throughout the plasma and that the liver tissue has an affinity for the uptake of Coumadin as early as 1 hr. Other soft tissue organs demonstrated some early uptake but the activity was minimal by 24 hrs while the liver still possessed about two times the activity of other tissues studied.

Kinetics of warfarin absorption in man

“…Rate of warfarin absorption. Rate of warfarin absorption was calculated in two ways: (1) In the first the time of maximum plasma concentration was found after oral dosing in 8 subjects, and the shape of the plasma concentration time curve was studied. This method does not depend on presupposing a certain pharmacokinetic model to fit the data.…”

“…This assumption may be valid since it is known that warfarin is largely distributed within the liver and kidneys. 1 The kinetic values so obtained were then applied to a second study in the 4 subjects in whom the same dose of warfarin was given orally and blood samples were taken at the times we have described. If, in these studies, an amount of drug (A) distributes into a volume (V), then at varying times after administration (t) equals the concentration of drug in plasma, tissues, and that eliminated.…”