Tranexamic Acid in Gynaecology Obsterics在妇产科止血环酸.pptVIP

Tranexamic Acid In Gynaecology Obstetrics Blood – The essence of Life LIFE GOES ON STOP BLOOD LOSS STOP BLOOD LOSS Women are always at Risk of Losing Blood FROM MENARCHE TO MENOPAUSE IN NORMALCY OR PREGNANCY IN HEALTH OR DISEASE DUB APH DUB PPH CX DUB HOW TO STOP IT? Events in Hemostasis 1) Vasoconstriction 2) Platelet plug formation 3) Blood clotting 4) Fibrinolysis Events in Haemostasis COAGULATION: Prothrombin Thrombin Fibrinogen Fibrin Clot forms Events in Haemostasis FIBRINOLYSIS: Plasminogen Plasmin dissolves Clot Events in Hemostasis COAGULATION AND FIBRINOLYSIS Events in Hemostasis COAGULATION AND FIBRINOLYSIS Presenting Tranexamic Acid TRANEXAMIC ACID Tranexamic Acid Tranexamic Acid Synthetic amino acid, first introduced in Sweden in1969. Chemically it is Tranexamic-stereo isomer of 1, 4, -aminomethylcyclohexane carboxylic acid. Formula – C8H15NO2. Molecular Wt.-157. Prevents fibrinolysis and breakdown of clot. It is a competitive inhibitor of plasminogen activation. At very high concentration, it is also a non competitive inhibitor of Plasmin. It is also a very weak inhibitor of thrombin. Tranexamic Acid Tranexamic acid inhibits conversion of plasminogen to plasmin, hence prevents breakdown of clot. Increases collagen synthesis which preserves the fibrin matrix and increases the tensile strength of the clot These actions of Tranexamic acid help in stabilizing the clot Mechanism of Action Tranexamic Acid Absorption after oral administration is 30-50% Food has no influence on absorption Peak plasma concentration after 3 hours Presystemic metabolism ~ nil. Bioavailability 30 – 50% Plasma half-life ~ 1.4h Is able to cross the blood-aqueous barrier in the eyes. Can also cross the damaged blood-brain barrier Rapidly diffuses into joint fluid and the synovial membrane. Crosses placenta and also into breast milk. Excretion unchanged 2 hours. Pharmacokinetics Tranexamic Acid Plasma protein binding is negligible Undergoes negligible metabolism in the body. M