Anticoagulant drugs Flashcards
Outline the coagulation cascade
What is another name for thrombin?
Activated factor II
What are the multiple pro-coagulative functions of thrombin?
Give examples of direct factor inhibitors
Direct thrombin inhibitors
Direct factor Xa inhibitors
Function of direct thrombin inhibitors
Bind thrombin in circulation and already attached to a clot
Function of factor Xa inhibitor
Greater effect on anticoagulation. Higher in the coagulation cascade
Lab parameters of direct thrombin inhibitors
Prolongs thrombin
Less effect on PT and aPTT
Lab parameters of factor Xa inhibitor
Prolongs PT and aPTT
No effect on thrombin
Direct thrombin inhibitors are especially useful when heparin causes an adverse reaction called..
HIT, or heparin induced thrombocytopenia
Side effects of direct thrombin inhibitors
GI symptoms like dyspepsia and gastritis
Bleeding when taken in excess
Direct thrombin inhibitors should not be discontinued suddenly as it leads to…
Increased thrombosis and risk of strokes
Give examples of direct thrombin inhibitors
Dabigatran etexilate and dabigatran
Give examples of direct factor Xa inhibitors
Apixaban, edoxaban and rivaroxaban
Side effects of direct factor Xa inhibitors
Bleeding
When are direct thrombin inhibitors used?
Replacement of heparin in HIT
When are direct factor Xa inhibitors used?
Alternative to Warfarin
Differentiate between unfractionated and fractionated heparin
Un: HMWH + LMWH
Frac: LMWH
Only LMWH/HMWH have an effect on thrombin
HMWH - in order to increase antithrombin III’s activity against thrombin, the thrombin needs to bind to the long tail of the heparin
What is used to measure the efficacy of heparin?
aPTT - longe than average
If heparin aPTT is greater than 100 then the patient must be suffering from..
Internal bleeding
Antithrombin also binds to active ________, which is a pivotal coagulation protein that converts ________ into ________
Antithrombin also binds to active factor X, which is a pivotal coagulation protein that converts prothrombin into thrombin
Function of heparin
Decreases activity of clotting factors thrombin and Xa by binding to antithrombin 3 and increasing its activity
Unfractioned heparin inhibits..
Factor Xa & thrombin
Fractioned heparin inhibits..
Factor Xa