Duloxetine - Warfarin Pharmacodynamic Study

To evaluate the blood clotting effects of multiple doses of warfarin at steady state when taken at the same time as multiple doses of duloxetine as measured by changes in the International Normalised Ratio. All subjects will begin dosing with warfarin, then after approximately 12 days, duloxetine 60 mg is added and subjects with stabilized INR will either continue dosing at 60 mg or have a dose increase to 120 mg.