Anticoagulants

Question 1

heparin MOA

Answer 1

antithrombin III activation, decreases IIa and Xa function`

Question 2

heparin antidote

Answer 2

protamine sulfate (very positive to sequester the heparin)

Question 3

what are the low molecular weight heparins

Answer 3

Enoxaparin, dalteparin: subQ, no lab. monitoring, not easily reversible

Question 4

heparin induced thrombocytopenia cause

Answer 4

IgG against heparin bound to platelet factor 4 (PF4) leads to activated platelets and thromobosis/thrombocytopenia

Question 5

Argatroban and bivalirudin

Answer 5

Derivatives of hirudin from leeches; inhibits thrombin directly. Use for patients with HIT

Question 6

warfarin MOA

Answer 6

interferes with normal synthesis and gamma-carboxylation of II, VII, IX, X, C, and S.

Question 7

warfarin metabolism

Answer 7

metabolized by P-450 pathway

Question 8

warfarin toxicity

Answer 8

teratogenic, skin tissue necrosis, drug/drug interactions

Question 9

apixaban and rivaroxaban

Answer 9

direct factor Xa inhibitors

Question 10

direct Xa inhibitors use

Answer 10

tx and ppx of dvt and PE (rivaroxaban), stroke ppx in a.fib. no coagulation monitoring. non reversible

Question 11

thrombolytics antidote

Answer 11

aminocaproic acid, fresh frozen plasma and cryoprecipitate can also be used to correct factor deficiencies

Question 12

do thrombolytics destroy clotting factors?

Answer 12

???

Question 13

What is tPA, rPA, and TNK-tPA

Answer 13

tissue Plasminogen activator, recominant plasminogenic activator, and tenecteplase tPA

Question 14

aspirin MOA

Answer 14

covalent acetylation of COX-1 and 2, platelets can’t produce more

Question 15

aspirin labs

Answer 15

inc. bleeding time, dec. TXA2 and prostaglandins, no effect on PT or PTT

Question 16

aspirin toxicity

Answer 16

CN VIII tinnitus, acute renal failure, interstitial nephritis.

Question 17

what does cox inhibition by ASA actually do?

Answer 17

prevents formation of TXA2, which facilitates platelet aggregation via gpIIb/IIIa. It also causes vasoconstriction in Prinzmetal’s

Question 18

clopidogrel, ticlopidine

Answer 18

ADP receptor inhibitors

Question 19

ADP receptor inhibitors MOA

Answer 19

prevent gpIIb/IIIa from entering platelets plasma membrane

Question 20

ticlopidine toxicity

Answer 20

neutropenia.

Question 21

ADP receptor inhibitor toxicity

Answer 21

TTP/HUS may be seen

Question 22

Cilostazol, dipyridamole MOA

Answer 22

Phosphodiesterase III inhibitor; inc. cAMP in plaelets, inhibiting platelet aggregation; vasodilators

Question 23

what does inc. cAMP in platelets actually do?

Answer 23

it increases Protein Kinase A which decreases aggregation, in smooth muscle: it prevents activation of myosin light chain kinase to allow for relaxation

Question 24

GPIIb/IIIa inhibitors

Answer 24

abciximab, eptifibatide, tirofiban

Question 25

GPIIb/IIIa inhibitors MOA

Answer 25

bind to the receptor on platelets preventing aggregation.