Tissue binding of warfarin.

: The binding of C-14 warfarin to liver, kidney, and skeletal muscle was evaluated among rats ranging in age from 29 to 832 days. Binding extensiveness was greatest for liver and least for skeletal muscle. The mean fraction bound remained relatively constant for each tissue among animals of all but the oldest age group. The oldest animals exhibited a lower fraction bound in each tissue. The influence of decreased tissue binding on its temporal profile in the blood is discussed.