Anti-coagulants

Question 1

Anticoagulants

a. protamine sulfate blocks the action of warfarin

Answer 1

a. False. Reverses the action of heparin

Question 2

b. heparin enhances antithrombin IV activity

Answer 2

b. False. Antithrombin III activity

Question 3

c. aspirin is used for the long-term prevention of stroke

Answer 3

c. True.

Question 4

d. tranexamic acid causes pulmonary emboli

Answer 4

d. True

Question 5

e. streptokinase degrades fibrin thrombi

Answer 5

e. True.

Question 6

Anticoagulants

a. heparin works through the blockade of antithrombin III

Answer 6

a. False, heparin enhances anti-thrombin III activity

Question 7

b. long-term aspirin use causes gastric ulceration as an adverse effect

Answer 7

b. True

Question 8

c. clopidogrel stimulates platelet receptor ADP binding

Answer 8

c. False. ADP receptor antagonist

Question 9

d. streptokinase is used in the treatment of myocardial infarcts

Answer 9

d. True (select cases)

Question 10

e. tranexamic acid stimulates the fibrinolytic action of plasmin

Answer 10

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.

Question 11

Anticoagulants / Antiplatelet drugs

a. clopidogrel – inhibits thromboxane A2

Answer 11

a. False. Clopidogrel is an ADP receptor antagonist

Question 12

b. warfarin – Vitamin K epoxide reductase inhibitor

Answer 12

b. True.

Question 13

c. heparin – enhances the activity of anti-thrombin III

Answer 13

c. True

Question 14

d. aspirin – blocks binding of ATP to platelets

Answer 14

d. False. Aspirin is cox 1 inhibitor and thus decreases txa2 synthesis

Question 15

e. enoxaparin – factor Xa inhibitor

Answer 15

e. True. LMW heparin is selective for factor Xa

Question 16

In the treatment of thromboembolism

a. streptokinase causes the breakdown of fibrin

Answer 16

a. True

Question 17

In the treatment of thromboembolism

b. heparin is a vitamin K antagonist

Answer 17

b. False. Antithrombin III

Question 18

In the treatment of thromboembolism

c. warfarin is preferred to low molecular weight heparin during pregnancy

Answer 18

c. False. Warfarin is CI in pregnancy

Question 19

In the treatment of thromboembolism

d. aspirin prevents the synthesis of thromboxane A2 in platelets

Answer 19

d. True

Question 20

In the treatment of thromboembolism

e. clopidogrel increases the risk of bleeding when taken at the same time as ibuprofen

Answer 20

e. True

Question 21

Clinical use of anticoagulants

a. warfarin-induced bleeding is reversed by freshly frozen plasma

Answer 21

a. True. Remember FFP

Question 22

b. heparin inactivates plasmin

Answer 22

b. False. Plasmin dissolves clots

Question 23

c. streptokinase is contraindicated in the presence of a haemorrhagic stroke

Answer 23

c. True

Question 24

d. orally administered heparin has a faster onset of action than parenteral heparin

Answer 24

d. False, parenteral = rapid onset of action

Question 25

e. dalteparin inhibits the activity of factor Xa

Answer 25

e. True. Dalteparin, enoxaparin and nadroparin are LMW heparin that selectively inhibit factor Xa

Question 26

Drugs used to manage thrombo-embolic disorders | a. fibrinolytic agents prevent the formation of blood clots

Answer 26

a. False. Fibrinolytic agents break down clots

Question 27

b. enoxaparin prevents clot formation

Answer 27

b. True (factor Xa inhibition)

Question 28

c. in the prevention of clot formation during the final trimester of pregnancy, warfarin is preferred to enoxaparin

Answer 28

c. False, warfarin is CI

Question 29

d. aspirin decreases platelet adherence

Answer 29

d. True

Question 30

e. alteplase dissolves fibrin in existing emboli

Answer 30

e. True

Question 31

Effects of drugs used to treat thrombo-embolic disorders | a. heparin causes bleeding as an adverse effect

Answer 31

a. True

Question 32

b. warfarin depletes active Vitamin K levels

Answer 32

b. True. Inhibits vitamin K epoxide reductase. Therefore, vitamin k will be reduced

Question 33

c. enoxaparin is safe to use in patients undergoing epidural anaesthesia

Answer 33

c. False. CI

Question 34

d. aspirin stimulates the synthesis of thromboxane A2 in the platelet

Answer 34

d. False, inhibits

Question 35

e. clopidogrel prevents platelet activation

Answer 35

e. True. ADP receptor antagonist

Question 36

In the prevention of clot formation | a. enoxaparin is administered orally

Answer 36

a. False, parenteral

Question 37

b. In the platelet, aspirin inhibits thromboxane A2 synthesis

Answer 37

b. True

Question 38

c. low molecular weight heparin binds to factor Xa

Answer 38

c. True

Question 39

d. dabigatran inhibits thrombin

Answer 39

d. True

Question 40

e. clopidogrel is an agonist at ADP receptors

Answer 40

e. False, antagonist

Question 41

Antithrombotics & anticoagulants | a. enoxaparin inhibits the activity of vitamin K epoxide reductase

Answer 41

a. False, this is warfarin

Question 42

b. warfarin activates vitamin K in the liver

Answer 42

b. False, inhibits the activity of vitamin K epoxide reductase

Question 43

c. rivaroxaban inhibits factor Xa

Answer 43

c. True

Question 44

d. heparin increases the activity of antithrombin III

Answer 44

d. True

Question 45

e. unfractionated heparin is administered intravenously

Answer 45

e. True

Question 46

In thromboembolic disorders | a. clopidogrel is an agonist at platelet ADP receptors

Answer 46

a. False antagonist

Question 47

b. aspirin increases platelet inositol triphosphate levels

Answer 47

b. False, decreases

Question 48

c. streptokinase causes antibody formation

Answer 48

c. True, foreign body causes antibodies

Question 49

d. warfarin decreases active protein S

Answer 49

d. True, warfarin affects clotting factors II, VII, IX, X, Protein C and S

Question 50

e. dabigatran inhibits the function of thrombin

Answer 50

e. True.

Question 51

In the management of thrombi, identify the agents that may cause paradoxical clot formation a. dabigatran

Answer 51

a. False

Question 52

In the management of thrombi, identify the agents that may cause paradoxical clot formation b. warfarin

Answer 52

b. True

Question 53

In the management of thrombi, identify the agents that may cause paradoxical clot formation c. aspirin

Answer 53

c. False

Question 54

In the management of thrombi, identify the agents that may cause paradoxical clot formation d. heparin

Answer 54

d. True

Question 55

In the management of thrombi, identify the agents that may cause paradoxical clot formation e. prasugrel

Answer 55

e. False