 Similar to the well publicized grapefruit juice effect, ongoing studies are evaluating the interaction potential of other dietary substances on drug disposition. This study is designed to determine whether the mechanism underlying the enhancement of the anticoagulative effect of warfarin by cranberry juice is due to inhibition of warfarin metabolism by the juice. A secondary objective is to determine whether cranberry juice elicits a grapefruit juice-type interaction with midazolam. 