25.03.3 Treatments for Bleeding Disorders

Uncontrolled bleeding occurs as a consequence of either a hereditary disease (haemophilia A, haemophilia B, von Willebrand’s disease) or an acquired condition (vitamin K deficiency, thrombocytopaenia, fibrinolysis after surgery).

Hereditary bleeding disorders

Haemophilic disease occurs as a result of a genetic lesion affecting one or more factors in the clotting cascade. Previous treatments involved administration of concentrated preparations of these factors isolated from donated human blood, a practice used less today with the ability of recombinant DNA technology to produce large amount of these components. Thus haemophilia A is treated with administration of clotting factor VIII and haemophilia B with clotting factor IX.

Acquired bleeding disorders

Treatment of acquired, uncontrolled bleeding is more problematical. In general, these episodes are caused by an individual being in a fibrinolytic state and treatment negates the cause of bleeding or potentiates the clotting mechanism.

Vitamin K1 administration promotes the formation of various clotting factors (II, VI, IX, X) and can reverse an abnormal coagulation status (for example treatment after surgery) or bleeding due to vitamin K1 deficiency.

Protamine sulphate is a heparin antagonist and is used to counteract the effect of this drug before and after surgery.

Tranexamic acid is a competitive inhibitor of the plasminogen activation process resulting in decreased production of plasmin and subsequent plasmin-mediated fibrinolysis. It is used to treat menorrhagia and patients with clotting disorders undergoing surgery. However, a potential side effect of treatment with tranexamic acid is intravascular thrombosis.

Similarly, aprotinin a serine protease used to reduce perioperative blood loss, also stops bleeding by blocking the action of plasmin.