Cholestatic hepatic injury related to warfarin exposure.

Despite the widespread use of oral anticoagulants derived from 4-hydroxycoumarin, there have been only a small number of well-defined cases of hepatotoxicity. We report a well-defined case of cholestasis following exposure to warfarin sodium (Coumadin). Inadvertent rechallenge reproduced the syndrome. Cholestasis may occur in response to exposure to derivations of 4-hydroxycoumarin.