chapter 22- Hemostasis and Thrombosis

Question 1

what is the mechanism of action of aspirin

Answer 1

inhibit platelet cyclooxyrgenase, thereby blocking thromboxane A2 generation and inhibiting platelet granule release reaction and platelet aggregation

Question 2

what is the mechanism of action of dipyridamole

Answer 2

inhibit platelet cAMP degradation and thereby decrease platelet aggregability

Question 3

what is the mechanism of action of ticlopidine, clopidogrel, and prasugrel

Answer 3

covalently modify platelet ADP receptor, thereby preventing receptor signaling and irreversibly inhibiting ADP-dependent platelet activation pathway

Question 4

what is the mechanism of action of eptifibatide, abciximab, tirofiban

Answer 4

bind to platelet receptor GPIIb-IIIa and thereby prevent binding of fibrinogen and other adhesive ligands

Question 5

what is the mechanism of action of warfarin

Answer 5

inhibit hepatic epoxide reductase that catalyzes the regeneration of reduced vitamin K

Question 6

what is the mechanism of action of unfractionated heparin

Answer 6

combines with antithrombin III and inhibits secondary hemostasis via nonselective inactivation of thrombin, factor Xa, factor XIa, and factor XIIa

Question 7

what is the mechanism of action of LMW heparins

Answer 7

combine with antithrombin III and inhibit secondary hemostasis via relatively selective inactivation of factor Xa

Question 8

what is the mechanism of action of fondaparinux

Answer 8

combine with antithrombin III and inhibit secondary hemostasis via highly selective inactivation of factor Xa

Question 9

what is the mechanism of action of hirudin-related agents (lepirudin, desirudin, bivalirudin) and argatroban

Answer 9

bind directly to thrombin and thereby inhibit secondary hemostasis

Question 10

what is the mechanism of action of recombinant activated protein C

Answer 10

proteolytically inactivates factors Va and VIIa

Question 11

what drugs are genetically engineered variants of t-PA with increased specificity for fibrin

Answer 11

tenecteplase, reteplase

Question 12

what is the mechanism of action of protamine

Answer 12

inactivates heparin by forming a stable 1:1 protamine: heparin compelx

Question 13

what is the mechanism of action of aprotinin

Answer 13

inhibits serine proteases, including plasmin, t-PA, and thrombin

Question 14

what is the mechanism of action of aminocaproic acid, tranexamic acid

Answer 14

analogues of lysine that bind to and inhibit plasminogen and plasmin

Question 15

what is the clinical application of aspirin

Answer 15

prophylaxis against transient ischemic attach, MI and thromboembolic strokes

Question 16

what are some adverse effects seen with aspirin

Answer 16

GI bleeding, acute renal insufficiency, reyes syndrome, tinnitus

Question 17

what are some contraindications for aspirin use

Answer 17

G6Pd deficiency, children with chickenpox or flu-like symptoms

Question 18

what is the clinical application of dipyridamole

Answer 18

prophylaxis against thromboembolic disorders, alternative to exercise in thallium myocardial perfusion imaging

Question 19

what are some adverse effects seen specific with IV route dipyridamole

Answer 19

exacerbation of aging, hypotension

Question 20

what is dipyridamole usually administered in combination with

Answer 20

aspirin or warfarin

Question 21

how may dipyridamole paradoxically induce angina

Answer 21

by causing coronary steal phenomenon

Question 22

what is the clinical application of ticlopidine

Answer 22

secondary prevention of thrombin strokes in patients intolerant of aspirin

Question 23

what are some adverse effects seen with ticlopidine

Answer 23

aplastic anemia, abnormal LFT

Question 24

what are some contraindications for ticlopidine use

Answer 24

active bleeding disorder, severe liver dysfunction

Question 25

what is the major contraindication for clopidogrel use

Answer 25

active bleeding disorder

Question 26

what is the clinical application of prasugrel

Answer 26

acute coronary syndromes; percutaneous coronary intervention; thrombosis prophylaxis

Question 27

why are some adverse effects seen with prasugrel

Answer 27

A-fib, bradycardia, hypertension, hyperlipidemia, backspin, epistaxis

Question 28

what are some contraindications for prasugrel use

Answer 28

active bleeding disorder, TIA, stroke

Question 29

what should prasugrel be used in combination with

Answer 29

aspirin

Question 30

what is the clinical application of eptifibatide

Answer 30

acute coronary syndromes, percutaneous coronary intervention

Question 31

what are some adverse effects seen with eptifibatide use

Answer 31

major bleeding, intracerebral hemorrhage, thrombocytopenia

Question 32

what is eptifibatide administered

Answer 32

parenteral admin

Question 33

what is the clinical application of tirofiban

Answer 33

acute coronary syndromes in patients undergoing angioplasty or atherectomy or managed medically

Question 34

what analogue is tirofiban

Answer 34

non peptide tyrosine analogue

Question 35

what is the most serious adverse effect with warfarin

Answer 35

bleeding

Question 36

what are some contraindications for warfarin use

Answer 36

pregnancy; regional/lumbar block anesthesia

Question 37

how do you monitor warfarin use

Answer 37

Prothrombin time

Question 38

what should patients who acquire severe hemorrhage due to warfarin receive

Answer 38

fresh frozen plasma

Question 39

what are some adverse reactions seen with unfractionated heparin

Answer 39

overly prolonged clotting time, mucosal ulceration,hematoma

Question 40

what is the clinical application of fondaparinux

Answer 40

prophylaxis and treatment of DVt and pulmonary embolism

Question 41

what are some contraindications of fondaparinux use

Answer 41

active major bleeding, severe renal impairment, bacterial endocarditis

Question 42

what is the clinical application of lepirudin

Answer 42

heparin induced thrombocytopenia

Question 43

what is the clinical application of desirudin

Answer 43

prophylaxis against DVT

Question 44

what is the clinical application of bivalirudin

Answer 44

anticoagulation in patients undergoing coronary angiography and angioplasty

Question 45

what are some contraindications to hirudin-related agents

Answer 45

active major bleeding, pregnancy, severe uncontrolled HTN, severe renal impairment

Question 46

what is the clinical application of argatroban

Answer 46

coronary artery thrombosis, prophylaxis in percutaneous coronary intervention, heparin-induced thrombocytopenia

Question 47

what are some adverse reactions seen with argatroban

Answer 47

cardiac arrets, cerebrovascular disease, ventricular tachycardia, sepsis, hypotension

Question 48

what are some contraindications or argatroban use

Answer 48

active major bleeding, severe liver impairment

Question 49

what is the clinical application of dabigatran

Answer 49

prevention of thromboembolism in non-valvular atrial fibrillation

Question 50

what are some adverse reactions seen with dabigatran

Answer 50

hemorrhage, severe hypertensive reaction

Question 51

what is the clinical application of r-APC

Answer 51

severe sepsis with organ dysfunction and high risk of death

Question 52

what is the major adverse reaction of r-APC

Answer 52

hemorrhage (increased risk of bleeding)

Question 53

what is the clinical application of streptokinase

Answer 53

ST elevation MI, life-threatening pulmonary embolism

Question 54

what is the clinical application of tenectaplase and reteplase

Answer 54

acute MI

Question 55

what is the clinical application of protamine

Answer 55

heparin overdose

Question 56

what are some adverse reactions seen with protamine

Answer 56

bradyarrythmia, hypotension, circulatory collapse, capillary leak

Question 57

how is protamine administered

Answer 57

IV

Question 58

what is the clinical application of aprotinin

Answer 58

reduce preoperative bleeding during CABG surgery

Question 59

what may aprotinin inhibit at higher doses

Answer 59

kallikrein

Question 60

what post operative condition may aprotinin increase the risk of in comparison to other anti-fibrinolytic agents

Answer 60

postoperative acute renal failure

Question 61

what is the clinical application of aminocaproic acid and tranexamic acid

Answer 61

disorder involving the fibrinolytic system; hemorrhage from increased fibrinolysis

Question 62

what are some adverse reactions seen with aminocaproic acid and tranexamic acid

Answer 62

bradyarrythmias, hypotension, thrombotic disodre, drug-induced myopathy

Question 63

what are some contraindications to aminocaproic acid and tranexamic acid use

Answer 63

DIC