hematologic agents

Question 1

what is the role of heparin sulfate on vascular endothelial cells?

Answer 1

binds to ATIII–>significantly incr rate of thrombin & factor Xa inactivation

Question 2

where is fibrinogen converted to fibrin?

Answer 2

the active site of thrombin (E1 site)

Question 3

does the antithrombin/heparin complex inhibit thrombin when bound or only when unbound?

Answer 3

does NOT inhibit thrombin bound to fibrin, only binds when thrombin is not bound to fibrin

Question 4

role of antithrombin/heparin complex

Answer 4

prevents thrombin from being inactivated at site of clot

Question 5

what type of thrombosis is a platelet poor clot?

Answer 5

venous thrombosis

DVT–>VTE–>PE

Question 6

are antiplatelet tx used for tx of DVT?

Answer 6

no. heparin usually administered

Question 7

which type of thrombosis is platelet rich?

Answer 7

arterial thrombosis

antiplatelet tx useful for tx

Question 8

where do arterial thrombosis normally occur?

Answer 8

on top of ruptured atherosclerotic plaques

Question 9

what is teh most common cause of MI and ischemic strokes?

Answer 9

arterial thrombosis

Question 10

common causes of thrombosis

Answer 10

cancer, A fib, placement of mechanical heart valves, lower limb orthopedic surgery, prolonged bed rest, OCP, factor V leiden

Question 11

what are used in primary prevention of MI or stroke?

Answer 11

antiplatelet drugs

Question 12

What is DAPT?

Answer 12

dual antiplatelet tx—>use to prevent MI, sudden cardiac death:
combo of ASA + P2Y12 antagonist

Question 13

main applications of anticoagulants

Answer 13

tx & prevent venous thrombosis/venous thromboembolism

• A fib
• major surgeries
• cancer
• DVT, pulmonary thromboembolism

Question 14

where is heparin normally found?

Answer 14

found in mast cells in the body, NOT in plasma

Question 15

does half life of heparin change as dose increases?

Answer 15

yes, half life increases as dose increases

Question 16

what is the antidote if too much heparin is administered?

Answer 16

protamine sulfate binds to and inactivates heparin molec

Question 17

which type of HIT is fatal?

Answer 17

type 2

Question 18

what happens in HIT II?

Answer 18

1. heparin binds PF4
2. antibodies generated towards PF4/heparin complex
3. antibodies bind platelets
4. platelets cleared by macrophages
5. venous & arterial thrombosis

Question 19

what is the anti-factor Xa assay used for?

Answer 19

directly measures activity of factor Xa

monitor LMWH + fondaparinux

Question 20

which drugs can be used to stop clotting at the site of the clot?

Answer 20

bicalrudin, lepirudin, argtroban, dibigatran

Question 21

wht is the target INR that you want to see after giving someone warfarin?

Answer 21

2-3

Question 22

drugs that potentiate warfarin’s effect do what to INR?

Answer 22

increase INR

Question 23

drugs that inhibit warfarin do what to INR?

Answer 23

decr INR

Question 24

if have renal insufficiency, & on warfarin, what will happen to INR?

Answer 24

1. renal insufficiency–>hypoalbuminemia
2. less albumin for warfarin to be bound to–>more warfarin in active form
3. INR incr

Question 25

why does necrosis happen with warfarin?

Answer 25

fall in protein C–>hypercoagulable state–>bleeding–>necrosis

Question 26

what are activators of plasminogens?

Answer 26

tPA, UPA

Question 27

fxn of streptokinase

Answer 27

fibrinolytic

Question 28

what are some fibrinolytic drugs?

Answer 28

activators of plasminogen:
streptokinase
uPA
tPA

Question 29

you might wan to immediately consider giving fibrinolytic drugs to someone with?

Answer 29

1. MI with ST elevation
2. new left bundle branch block
   (indicators of acute ischemic MI)