Hematological agents II

Question 1

What is type I heparin induced thrombocytopenia? What is the consequence of this?

Answer 1

Heparin can increase platelet aggregation which causes a decrease in circulation platelet numbers

Little clinical consequence

Question 2

What is type II heparine induced thrombocytopenia?

Answer 2

Heparine can bind platelet factor 4, which some pts develop antibodies against. This causes thrombosis

Question 3

Which type of heparin causes HIT: fractionated or unfractionated?

Answer 3

unfractionated

Question 4

Which are more common in HIT: venous or arterial thromboses?

Answer 4

Venous

Question 5

Who are more affected by HIT: men or women?

Answer 5

Women

Question 6

How long does it take platelet counts to fall following heparin administration?

Answer 6

5-10 days

Question 7

What is enoxaparin?

Answer 7

Lower molecular weight heparin

Question 8

What is low molecular weight heparin called?

Answer 8

Enoxaparin

Question 9

What is the major disadvantage to low molecular weight heparin? (2)

Answer 9

Cannot deactiveate thrombin

Protamine only partially reverses it

Question 10

What are the advantages to low molecular weight heparin? (2)

Answer 10

Easier to dose

Lower risk for HIT

Question 11

What disease contraindicates low molecular weight heparin?

Answer 11

Renal insufficiency

Question 12

What is fondaparinux?

Answer 12

Synthetic analog of AT binding pentasaccharide sequence

Question 13

What is the MOA of fondaparinux?

Answer 13

Binds to antithrombin and increases rate of factor X inhibition

Question 14

True or false: protamine is only partially effectie against fondaparinux

Answer 14

False–not at all effective

Question 15

What is the major contraidication with fondaparinux?

Answer 15

Renal disease

Question 16

What is the monitoring assay for fondaparinux?

Answer 16

anti-factor Xa assay

Question 17

True or false: monitoring of fondaparinux and LMWH is not as intensive as monitoring regular heparin

Answer 17

True

Question 18

What is the MOA of hirudin?

Answer 18

Direct thrombin inhibitor at both active sites

Question 19

Do direct thrombin inhibitors inhibit factor 10?

Answer 19

no

Question 20

How do you administer hirudin?

Answer 20

parenterally

Question 21

What is the MOA of lepirudin?

Answer 21

Direct thrombin inhibitor at both active sites

Question 22

How do direct thrombin inhibitors work?

Answer 22

Directly binding to the active site in thrombin that cleaves fibrinogen into fibrin

Question 23

What is the MOA of argatroban?

Answer 23

Direct thrombin inhibitor at the active site

Question 24

What is the MOA of dabigitran?

Answer 24

Direct thrombin inhibitor at the active site

Question 25

Which direct thrombin inhibitor is given orally?

Answer 25

Dabigitran

Question 26

What is the major advantage of DTIs vs heparin?

Answer 26

can inhibit thrombin bound to fibrin

Question 27

What type of drug should you use instead of heparin in cases of HIT?

Answer 27

Direct thrombin inhibitor

Question 28

What is the MOA of bivalirudin?

Answer 28

Inhibits thrombin by binding directly to active site (direct thrombin inhibitor)

Question 29

What is the drug used to reverse direct thrombin inhibitors

Answer 29

There is none

Question 30

What is the MOA of warfarin?

Answer 30

Competes with Vit K for Vit K reductase

Question 31

What are the factors that need vitamin K?

Answer 31

10 9 7 and 2 (and protein C and S)

Question 32

What does vitamin K reductase do?

Answer 32

Reduces the oxidized form of Vit K, that is used in factor activation

Question 33

How long does it take for warfarin to take full effect? Why?

Answer 33

3-5 days | Only affects new factors

Question 34

What is the enzyme that degrades warfarin? What is the significance of this?

Answer 34

CYP2C9 pts with polymorphisms need lower dose

Question 35

Why does warfarin have such a high Vd?

Answer 35

Plasma protein bound

Question 36

What is the test to monitor warfarin?

Answer 36

PT

Question 37

What are the general steps of performing a PT?

Answer 37

- blood collected in Ca free tube - thromboplastin added - Ca added - time

Question 38

Generally, what types of drugs are contraindicated with warfarin?

Answer 38

Any drug that interferes with Vit K absorption

Question 39

Where does Vit K come from? What drugs, then, have to be carefully used when a pt is on warfarin?

Answer 39

Gut bacteria | Abx

Question 40

Potentiate or reduce the anticoagulant effect of warfarin: NSAIDs. Why?

Answer 40

Potentiate | Interfere with primary hemostasis

Question 41

Potentiate or reduce the anticoagulant effect of warfarin: SSRIs

Answer 41

Potentiate

Question 42

Potentiate or reduce the anticoagulant effect of warfarin: anti-platelet drugs

Answer 42

Potentiate

Question 43

Potentiate or reduce the anticoagulant effect of warfarin: drugs that decrease hepatic metabolism

Answer 43

potentiate

Question 44

Potentiate or reduce the anticoagulant effect of warfarin: statins . Why?

Answer 44

Potentiate | Use same CYP enzyme, and saturate it

Question 45

Potentiate or reduce the anticoagulant effect of warfarin: rifampin. Why?

Answer 45

Reduce

Question 46

Potentiate or reduce the anticoagulant effect of warfarin: carbamazepine. Why?

Answer 46

reduce | Increase hepatic elimination of the drug

Question 47

Potentiate or reduce the anticoagulant effect of warfarin: renal insufficiency. Why?

Answer 47

Potentiate since hypoalbuemia

Question 48

Potentiate or reduce the anticoagulant effect of warfarin: decreased hepatic function

Answer 48

Reduce

Question 49

What is the severe adverse side effect of warfarin use? What causes this?

Answer 49

Necrosis | Precipitous fall in vitamin C

Question 50

What is the therapeutic INR range for warfarin?

Answer 50

2-3

Question 51

What are the two things to administer a pt with too high of an INR d/t warfarin use?

Answer 51

Vit K | Administer fresh plasma

Question 52

What is the MOA of rivaroxaban?

Answer 52

Direct inhibitor of factor X

Question 53

What is the MOA of apixaban?

Answer 53

Directly inhibits factor X

Question 54

What are the benefits of the newer oral anticoagulants like rivaroxaban, apixaban, and dabigatran?

Answer 54

- Faster onset - Low food/drug interactions - Predictable effect

Question 55

IS warfarin or heparin safe to take during pregnancy?

Answer 55

Warfarin, no | Heparin, yes

Question 56

What is the main protein involved in the fibrinolytic system? What activates it?

Answer 56

Plasmin | tPA

Question 57

Why isn't there much activation of plasminogen in the plasma if there's tPA?

Answer 57

Both have higher affinity when bound to fibrin

Question 58

What is the inhibitor in the plasma that will inhiit plasmi?

Answer 58

Alpha2 plasma inhibitor

Question 59

How, generally, do the fibrinolytic drugs work?

Answer 59

Activate plasmin from plasminogen

Question 60

What is the MOA of steptokinase?

Answer 60

forms a complex with plasminogen

Question 61

What is the MOA of urokinase?

Answer 61

Natrual activator of plasmin, produced by the kidney

Question 62

What are the two tPA agents used in clinic?

Answer 62

Alteplase | Reteplase

Question 63

What are the adverse effects of streptokinase?

Answer 63

anaphylaxis

Question 64

When are fibrinolytic drugs used?

Answer 64

STEMI or new LBBB

Question 65

Should you use thrombolytics in NSTEMIs?

Answer 65

No

Question 66

What is the MOA of aminocaproic acid?

Answer 66

Blocks interaction of plasmin with fibrin, thus preventing fibrin degradation

Question 67

What is the MOA of tranexamic acid?

Answer 67

Blocks interaction of plasmin with fibrin, thus preventing fibrin degradation

Question 68

What are aminocaproic acid and tranexamic acid used for?

Answer 68

Hemophila treatment