Anti-Coagulants I

Question 1

warfarin

Answer 1

given oral only
-inhibit K dependent factors
II, VII, IX, X, protein C and S

without the two carboxy residues - cannot bind calcium or phospholipid

inhibits vitamin K epoxide reductase

Question 2

heparin

Answer 2

only IV or subQ
-aka unfractionated

activates antithrombin III
-inactivates IIa, IXa, Xa, XIa, XIIa

prolongs aPTT and thrombin time

Question 3

low MW heparin

Answer 3

give subQ
-prophylaxis/treatment of MI, DVT, PE

acts only on Xa
-no binding site for IIa

longer half life than heparin
no monitoring required
less protein binding than heparin
no endo cell binding
no dose-dependent clearance

Question 4

fondaparinux

Answer 4

factor Xa inhibitor

• subQ injection
• analog of heparin

Question 5

dabigatran

Answer 5

oral anticoag

• binds to thrombin
• inhibits clot-bound and circulating thrombin
• rapid onset

Re-ly and Re-cover trials - non-inferior and similar safety to warfarin**

no monitoring required

no antidote
expensive

Question 6

aspirin

Answer 6

inhibits TXA2 formation (blocks COX-1)
-inhibits platelet aggregation

for prophylaxis tx of MI, stroke, and PAD

Question 7

clopidogrel

Answer 7

blocks P2Y12 - ADP receptor on platelets - IRREVERSIBLE
-no aggregation

inactive prodrug

prophylaxis of stroke, MI, PAD, acute coronary syndrome

Question 8

dipyridamole

Answer 8

blocks platelet aggreagation
-inhibits adenosine uptake and is cAMP phosphodiesterase inhibitor

prophylaxis of arterial thromboembolism

prosthetics and bypass grafts

angioplasty phophylaxis

Question 9

abciximab

Answer 9

monoclonal antibody for GpIIbIIIa complex

-no platelet aggregation

Question 10

aletplase

Answer 10

plasminogen activator

acute MI

Question 11

reteplase

Answer 11

plasminogen activator

acute MI

diffuses through clot more freely

Question 12

tenecteplase

Answer 12

plasminogen activator

single bolus given over 5-10sec

acute MI

Question 13

streptokinase

Answer 13

non-enzyme plasminogen activator

acute MI

from beta hemolytic strep

• many have antibodies
• must saturate with loading dose

Question 14

5HT

Answer 14

serotonin

-activator of platelet aggregation

Question 15

PGI2

Answer 15

prostacyclin

-inhibitor of platelet aggregation

Question 16

arterial thrombus

Answer 16

white clot

• not many RBCs - sheared off
• high blood flow

Question 17

venous thrombus

Answer 17

red clot

• lots of RBCs - stasis
• can be very long tali

Question 18

enoxaparin

Answer 18

low MW heparin

Question 19

heparin monitoring

Answer 19

aPTT 1.5 - 2.5x control

Question 20

warfarin monitoring

Answer 20

PT - normalized with INR

2-3

Question 21

subQ minidose of heparin

Answer 21

post-surgery prophylaxis

Question 22

low MW heparin monitoring

Answer 22

not necessary

Question 23

rivaroxaban

Answer 23

oral anticoag
inhibits factor Xa

no monitoring
no antidote
expensive

Question 24

apixaban

Answer 24

oral anticoag
inhibit factor Xa

no monitoring
no antidote
expensive

Question 25

eptifibatide

Answer 25

blocks fibrinogen binding to GpIIbIIIa

Question 26

tirofiban

Answer 26

blocks fibrinogen binding to GpIIbIIIa

Question 27

lepirudin

Answer 27

binds thrombin

Question 28

bivalirudin

Answer 28

binds to thrombin

Question 29

argatroban

Answer 29

binds to thrombin Tx for HIT

Question 30

rapid anticoag

Answer 30

heparin low MW heparin fondaparinux

Question 31

slow anticoag

Answer 31

warfarin

Question 32

heparin

Answer 32

antithrombin III activation most important - effect on IIa and Xa inhibition

Question 33

HIT

Answer 33

heparin induce thrombocytopenia type II - severe - antibodies against platelet factor 4

Question 34

Tx of acute MI

Answer 34

aspirin therapy, O2, nitro, morphine then thrombolytics/ procedure then IV heparin

Question 35

DIC

Answer 35

Tx heparin

Question 36

heparin antidote

Answer 36

protamine sulfate - strongly basic protein - given IV - binds up heparin need to give slow

Question 37

surgery of abdomen, hip, knee

Answer 37

prophylaxis for DVT - enoxaparin

Question 38

Q wave MI

Answer 38

enoxaparin with asprin

Question 39

acute DVT

Answer 39

enoxaparin with warfarin

Question 40

IV direct thrombin inhibitors

Answer 40

IV only hirudin, lepirudin, bivalirudin, argatroban

Question 41

vit K epoxide reductase

Answer 41

inhibited by warfarin

Question 42

t-1/2 for warfarin

Answer 42

40 hours 5 half lifes for plateau

Question 43

contraindicated in pregant

Answer 43

warfarin - congenital anomalies

Question 44

warfarin overdose

Answer 44

treatment with vit K1 | infusion of fresh-frozen plasma

Question 45

oral direct thrombin inhibitors

Answer 45

dabigatran rivaroxaban apixaban for prevention of thromboembolic stroke, PE, DVT

Question 46

high dose of aspirin

Answer 46

COX-2 blocker -prostacyclin blocked prostacyclin is an inhibitor of platelet aggregation and vasodilator

Question 47

aspirin and acute MI

Answer 47

loading dose - 162mg continue 160mg daily for 30 days

Question 48

antiplatelet effect of aspirin

Answer 48

80mg daily

Question 49

ticlopidine

Answer 49

inhibits ADP receptor on platelets can cause TTP, aplastic anemia, agranulocytosis

Question 50

cilostazol

Answer 50

inhibit phosphodiesterase III - results in increased cyclic AMP - and decreased platelet aggreagation - also stimulates vasodilation Tx of intermittent claudication

Question 51

pentoxifylline

Answer 51

decrease blood viscosity improve erythrocyte felxibility for intermittent claudication

Question 52

normal platelet levels

Answer 52

130,000 - 400,000

Question 53

aPTT

Answer 53

for intrinsic pathway monitor unfractionated heparin

Question 54

PT

Answer 54

measure extrinsic factors monitor warfarin - normalized to INR

Question 55

thrombin time

Answer 55

no Ca added | -clotting time independent on thrombin formation

Question 56

warfarin drug interactions

Answer 56

INCREASE WARFARIN RESPONSE inhibit hepatic metabolism displacement from plasma binding sites interfere with vit K DECREASE WARFARIN RESPONSE induce enzymes for warfarin metabolism -reduced absorption, increased synthesis of clotting factors, hemoconcenration of clotting factors