Anti-coagulants Flashcards
Anticoagulants
a. protamine sulfate blocks the action of warfarin
a. False. Reverses the action of heparin
b. heparin enhances antithrombin IV activity
b. False. Antithrombin III activity
c. aspirin is used for the long-term prevention of stroke
c. True.
d. tranexamic acid causes pulmonary emboli
d. True
e. streptokinase degrades fibrin thrombi
e. True.
Anticoagulants
a. heparin works through the blockade of antithrombin III
a. False, heparin enhances anti-thrombin III activity
b. long-term aspirin use causes gastric ulceration as an adverse effect
b. True
c. clopidogrel stimulates platelet receptor ADP binding
c. False. ADP receptor antagonist
d. streptokinase is used in the treatment of myocardial infarcts
d. True (select cases)
e. tranexamic acid stimulates the fibrinolytic action of plasmin
e. False. Tranexamic acid exerts an anti-haemorrhagic activity by inhibiting the fibrinolytic properties of plasmin. It is a competitive inhibitor of the conversion of plasminogen to plasmin. At high concentrations it is a non-competitive inhibitor of plasmin. The activity of the tranexamic acid-plasmin complex on the activity on fibrin is lower than the activity of free plasmin alone.
Anticoagulants / Antiplatelet drugs
a. clopidogrel – inhibits thromboxane A2
a. False. Clopidogrel is an ADP receptor antagonist
b. warfarin – Vitamin K epoxide reductase inhibitor
b. True.
c. heparin – enhances the activity of anti-thrombin III
c. True
d. aspirin – blocks binding of ATP to platelets
d. False. Aspirin is cox 1 inhibitor and thus decreases txa2 synthesis
e. enoxaparin – factor Xa inhibitor
Xa
e. True. LMW heparin is selective for factor
In the treatment of thromboembolism
a. streptokinase causes the breakdown of fibrin
a. True
In the treatment of thromboembolism
b. heparin is a vitamin K antagonist
b. False. Antithrombin III
In the treatment of thromboembolism
c. warfarin is preferred to low molecular weight heparin during pregnancy
c. False. Warfarin is CI in pregnancy
In the treatment of thromboembolism
d. aspirin prevents the synthesis of thromboxane A2 in platelets
d. True
In the treatment of thromboembolism
e. clopidogrel increases the risk of bleeding when taken at the same time as ibuprofen
e. True
Clinical use of anticoagulants
a. warfarin-induced bleeding is reversed by freshly frozen plasma
a. True. Remember FFP
b. heparin inactivates plasmin
b. False. Plasmin dissolves clots
c. streptokinase is contraindicated in the presence of a haemorrhagic stroke
c. True
d. orally administered heparin has a faster onset of action than parenteral heparin
d. False, parenteral = rapid onset of action
e. dalteparin inhibits the activity of factor Xa
e. True. Dalteparin, enoxaparin and nadroparin are LMW heparin that selectively inhibit factor Xa
Drugs used to manage thrombo-embolic disorders
a. fibrinolytic agents prevent the formation of blood clots
a. False. Fibrinolytic agents break down clots
b. enoxaparin prevents clot formation
b. True (factor Xa inhibition)
c. in the prevention of clot formation during the final trimester of pregnancy, warfarin is preferred to enoxaparin
c. False, warfarin is CI
d. aspirin decreases platelet adherence
d. True
e. alteplase dissolves fibrin in existing emboli
e. True
Effects of drugs used to treat thrombo-embolic disorders
a. heparin causes bleeding as an adverse effect
a. True
b. warfarin depletes active Vitamin K levels
b. True. Inhibits vitamin K epoxide reductase. Therefore, vitamin k will be reduced
c. enoxaparin is safe to use in patients undergoing epidural anaesthesia
c. False. CI
d. aspirin stimulates the synthesis of thromboxane A2 in the platelet
d. False, inhibits
e. clopidogrel prevents platelet activation
e. True. ADP receptor antagonist
In the prevention of clot formation
a. enoxaparin is administered orally
a. False, parenteral
b. In the platelet, aspirin inhibits thromboxane A2 synthesis
b. True
c. low molecular weight heparin binds to factor Xa
c. True
d. dabigatran inhibits thrombin
d. True
e. clopidogrel is an agonist at ADP receptors
e. False, antagonist
Antithrombotics & anticoagulants
a. enoxaparin inhibits the activity of vitamin K epoxide reductase
a. False, this is warfarin
b. warfarin activates vitamin K in the liver
b. False, inhibits the activity of vitamin K epoxide reductase
c. rivaroxaban inhibits factor Xa
c. True
d. heparin increases the activity of antithrombin III
d. True
e. unfractionated heparin is administered intravenously
e. True
In thromboembolic disorders
a. clopidogrel is an agonist at platelet ADP receptors
a. False antagonist
b. aspirin increases platelet inositol triphosphate levels
b. False, decreases
c. streptokinase causes antibody formation
c. True, foreign body causes antibodies
d. warfarin decreases active protein S
d. True, warfarin affects clotting factors II, VII, IX, X, Protein C and S
e. dabigatran inhibits the function of thrombin
e. True.
In the management of thrombi, identify the agents that may cause paradoxical clot formation
a. dabigatran
a. False
In the management of thrombi, identify the agents that may cause paradoxical clot formation
b. warfarin
b. True
In the management of thrombi, identify the agents that may cause paradoxical clot formation
c. aspirin
c. False
In the management of thrombi, identify the agents that may cause paradoxical clot formation
d. heparin
d. True
In the management of thrombi, identify the agents that may cause paradoxical clot formation
e. prasugrel
e. False
