Anticoagulation and Thrombosis PDF

Anticoagulation and Thrombosis Rehab S. Abelrahman, PhD Associate Professor of Pharmacology &Toxicology College of Pharmacy, Taibah University  Coagulation: Coagulation is a complex process by which blood forms clots. It is an important part o...

Anticoagulation and Thrombosis Rehab S. Abelrahman, PhD Associate Professor of Pharmacology &Toxicology College of Pharmacy, Taibah University  Coagulation: Coagulation is a complex process by which blood forms clots. It is an important part of hemostasis (the cessation of blood loss from a damaged vessel). Disorders of coagulation can lead to an increased risk of bleeding (hemorrhage) or clotting (thrombosis). Hemostasis is maintained in the body via three mechanisms: 1- Vascular spasm, Damaged blood vessels constrict. 2- Platelet plug formation, Platelets adhere to damaged endothelium to form platelet plug (primary hemostasis) 3- Blood Coagulation , Clots form upon the conversion of fibrinogen to Fibrin (secondary hemostasis). ‫الصورة لإلطالع‬  What are the three pathways of coagulation? Coagulation consists of three pathways, the extrinsic, intrinsic, and common pathways, that interact together to form a stable blood clot. The extrinsic and intrinsic coagulation pathways both lead into the final common pathway by independently activating factor X.  The extrinsic pathway involves initiation by factor III (i.e., tissue factor) and its interaction with factor VII. Whereas, factors XII, XI, IX, and VIII are utilized in the intrinsic pathway. Then, the common pathway uses factors X, V, II, I, and XIII. What triggers extrinsic and intrinsic pathways: Extrinsic—Release of biochemicals from broken blood vessels/damaged tissue. Intrinsic—No tissue damage, blood contacts damaged endothelial layer of blood vessel walls.  What is the main goal of coagulation? The main goal of coagulation is to form a stable blood clot to stop bleeding and allow time for the tissue to be repaired. Coagulation disorders are disorders which affect the coagulation cascade and coagulation cascade can either cause excessive or inadequate clotting. Coagulation disorders usually involve a deficiency in at least one clotting factor, clotting factor and the most common disorders include, hemophilia, and vitamin k deficiency. hemophilia vitamin k deficiency  What is a prothrombin time (PT/INR) test? Test measures how quickly your blood clots Abnormal PT results: A high PT test result or INR level means it takes more time than usual for your blood to clot. If you’re not taking warfarin, it could be a sign of a bleeding or blood clotting disorder or a problem with your liver. A high result could also mean you’re not getting enough vitamin K. Vitamin K blood clot Vitamin K plays a key role in helping the blood clot, which prevents excessive bleeding. Anticoagulants drugs Anticoagulants are drugs that prevent or delay clotting of blood. The most common anticoagulants are Heparin, and Warfarin Both (Heparin, and Warfarin) are an anticoagulant (blood thinner). Both (Heparin, and Warfarin) reduces the formation of blood clots