 - Subject is using any of the following medications : heparin, ticlopidine, ginko in subjects taking warfarin, oral steroids 7 days per month, chronic use of strong CYP3A4 inhibitors HIV protease inhibitors, macrolide antibiotics and nefazodone, chronic use of CYP3A4 inducers carbamazepine, phenytoin, rifampin, and St. Johns Wort. 