A Study to Explore the Pharmacodynamic Changes When Transitioning From Rivaroxaban to Warfarin in Healthy Volunteers

Inclusion Criteria: * Volunteers must agree to provide a blood sample for pharmacogenomic testing and must have less than 3 of the variant CYP2C9 and VKORC1 gene alleles associated with increased warfarin sensitivity if their genetic status regarding these alleles is not previously known * Have coagulation test results (INR, PT, and activated partial thromboplastin time (aPTT) within clinically acceptable limits, blood pressure (after the volunteer is supine for 5 minutes) between 90 and 140 mmHg systolic, inclusive, and between 50 and 90 mmHg diastolic * Have a body mass index (BMI) between 18 and 30 kg/m2 (inclusive), and body weight of not less than 50 kg * Be a Non-smoker (Volunteers may not use nicotine-containing products within 3 months prior to study drug administration Exclusion Criteria: * Have a history or current clinically significant medical illness, including (but not limited to) of intracranial tumor or aneurysm * Have history of gastrointestinal disease (e.g., Crohn's disease) which could result in impaired absorption of the study drugs or history of clinically significant hemoptysis, excessive bruising, bleeding from nose or gums or known disorders with increased bleeding risk (e.g., acute gastritis, acute peptic ulcer) or history of any bleeding diathesis. Concomitant use (also within the last 2 weeks before start of the study) of drugs that influenced the coagulation system, e.g., antiplatelet drugs (e.g., acetylsalicylic acid, ticlopidine and clopidogrel * abciximab, tirofiban and integrelin) or other anticoagulants (antithrombins, unfractionated heparins, low molecular weight heparins and hirudin, coumadin-type anticoagulants phenprocoumon, warfarin, dabigatran, probenecide) * Use of medications known to affect the metabolic pathways (CYP3A4, or P-gp) within 14 days of study admission