Systemic anticoagulants

SYSTEMIC ANTICOAGULANTS
(In vivo anticogulants)

Heparin

  • Heparin is used both as in vitro and in vivo anticoagulant. Heparin is used parenterally as an anticoagulant.
  • It has direct and almost instantaneous action on the coagulation process.
  • Heparin is present in mast cells along with histamine and serotonin and is prepared commercially from bovine lung and porcine intestinal mucosa.
  • Heparin is a highly negatively charged mucopolysaccharide having larger molecular size and hence is administered parenterally.
  • Heparin prolongs the clotting time of blood both in vivo and in vitro.
  • Heparin prevents fibrin formation in the process of coagulation.
  • It increases the activity of antithrombin III.
  • Antithrombin III then inhibits the conversion of prothrombin to thrombin by thromboplastin.
  • Antithrombin III also directly inactivates thrombin in the presence of heparin.
  • Heparin decreases aldosterone secretion, increases the concentration of free thyroxine.
  • It slows wound healing and depresses cell mediated immunity.
Last modified: Wednesday, 25 April 2012, 11:59 AM