This document discusses various treatments and medications for bleeding and anticoagulation. It describes different classes of anticoagulant drugs that prevent blood clotting, including coumarins (vitamin K antagonists) like warfarin, heparin, and newer direct factor Xa and thrombin inhibitors. It provides details on specific medications within each class, their mechanisms of action, uses, advantages, disadvantages, and adverse effects. Alternative anticoagulants explored include antithrombin protein therapeutics and substances from snake venoms or leeches.