Antiplatelet, anticoagulant and thombolytic drugs Flashcards
Where would an arterial thrombus (white thrombus) become lodged?
Brain (stroke) or other organ
Where would a venous (red thombus) become lodged?
Lungs (pulmonary embolus)
In vivo pathway tissue factors
VIIa
Contact pathway factors
XIIa and IXa
X becomes Xa and what does this to?
Changes prothrombin (II) to thrombin IIa this then converts fibrinogen to fibrin
Xa inhibitor
Rivaroxiban
Thrombin inhibitors
Dabigatran etexilate
Bivalirudin
What state must vitamin K be in to act as an essential cofactor?
In its reduced form (hydroquinone)
How does warfarin work?
Structurally similar to vitamin K, competes with vit. K for binding to vitamin K reductase
(prevents conversion of epoxide to hydroquinone)
Which factors does warfarin inactivate?
II, VIII, IX and X
Pregnancy, hypothyroidism and clotting factors?
Pregnancy = increased synthesis of clotting factors Hypothyroidism = decreased degradation of clotting factors
Treatment for overdose of warfarin?
Vitamin K or concentrate of plasma clotting factors
Enoxaparin
Dalteparin
LMWH
Name 2 LMWH
Enoxaparin
Dalteparin
How is heparin administered?
IV or SC
How are LMWH administered?
SC
How do you determine optimum dosage for heparin?
In vitro clotting
How are LMWH excreted?
Via the kidneys
Heparin inhibits which factors?
IIa and Xa
LMWH inhibits which factor?
Xa
Adverse effects of heparin and LMWH?
Haemorrhage
Osteoporosis
Hypoaldosteronism
Hypersensitivity reactions
Direct thrombin inhibitor
Dabigatran etexilate
Factor Xa inhibitor
Rivaroxiban
How are platelets cross linked?
Fibrinogen
