ABSTRACT
Learning objectives ■ Coagulation of blood ■ Heparin ■ Low molecular weight heparins ■ Protamine sulphate – heparin antidote ■ Hirudins ■ Danaparoid
sodium ■ Fondaparinux
Learning objectives Know the difference between the extrinsic and intrinsic clotting systems. ■ Be able to list different drugs or drug types which target the coagulation ■ cascade. Know the nature, uses and dangers associated with heparin. ■ Be able to explain what low molecular weight heparins are, give some ■ examples and list their advantages over heparin. Know what hirudins and heparinoids are and be able to give examples. ■
Coagulation of blood Is the conversion of blood from a liquid to a solid ( ■ see Figure 22.1). Is primarily a device to arrest bleeding from a wound. ■ Is initiated by: ■
the intrinsic pathway is activated when blood comes into contact ♦ with sub-endothelial connective tissues or with negatively charged surfaces exposed as a result of tissue damage the extrinsic pathway is an alternative route for the activation of the ♦ clotting cascade, providing a more rapid response to tissue injury, generating activated factor X almost instantaneously, compared to the seconds or even minutes taken by the intrinsic pathway to activate factor X. An important function of the extrinsic pathway is to augment the activity of the intrinsic pathway.
