Ancrod--therapeutic use Anticoagulants--adverse effects Antithrombins--therapeutic use Chondroitin Sulfates--therapeutic use Dermatan Sulfate--therapeutic use Drug Combinations Heparin--adverse effects Heparin, Low-Molecular-Weight--therapeutic use Heparitin Sulfate--therapeutic use Hirudin Therapy Hirudins--analogs & derivatives Humans Recombinant Proteins--therapeutic use Thrombocytopenia--chemically induced Thrombosis--drug therapy Warfarin--therapeutic use