The Johns Hopkins Center for Bariatric Surgery is interested in conducting a pharmacokinetic study of apixaban (an oral anticoagulant with FDA approval for use of VTE prophylaxis and treatment) in the obese adult population to determine if bariatric surgery influences apixaban exposure. More interesting would be to see how the dose may need to change pre- vs. post-bariatric surgery (this will be important for physicians as more and more patients undergo this procedure worldwide and many may require anticoagulation in their future healthcare).