title: Letter: Heparin levels and blood coagulation.
mesh_terms: D000991:Antithrombins / Q000378:metabolism; D001777:Blood Coagulation / Q000187:drug effects*; D006493:Heparin / Q000494:pharmacology*; D013917:Thrombin / Q000378:metabolism
chemical_list: D000991:Antithrombins; D006493:Heparin; D013917:Thrombin