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Flashcards in Antithrombotics Deck (39):
1

Antiplatelet drug classes (4)

COX-1 inhiitors
PDE inhibitors
ADP receptor antagonists
GP IIb/IIIa antagonists

2

ADP-recpetor antagonist

clopidogrel

3

GP IIb/IIIa antagonist

abciximab

4

MOA of clopidogrel

Irriversibly antagonizes ADP receptor reducing inactivation of AC, increasing cAMP and increasing PKA, leading to reduced platelet aggregation

5

MOA of abciximab

binds to GP to prevent them from crosslinking through fibrinogen bridge

6

Pharmaco genetics of clopidogrel

prodrug metabolized by CYP2C19. Black boxed warning

7

Pharmacokinetics of clopidogrel

orally effective, maximal efficacy 8-11 days

8

Therapeutic use of colpidogrel

alternative to low dose asprin
reduces rate of stroke, MI and death in those with recent stroke, MI, ACS, PAD
In combination with asprin for prevention of coronary stent thrombosis and ACS

9

Adverse effects of colpidogrel

bleeding
thrombotic thrombocytopenic purpura

10

Drug interactions with colpidogrel

avoid NSAIDS
CYP2C19 inhibitors, omeprazole

11

Pharmacokinetics of abciximab

half life 10 min duration of action 48 hours due to irreversible binding

12

Therapeutic use of abciximab

most effective, most expensive
short term in combo with asprin to prevent ischemic events in hospital setting

13

Adverse effects of abciximab

bleeding, anaphylaxis

14

Heparin MOA

indirect inhibitors of thrombin and/or Xa through antithrombin

15

Enoxaparin MOA

~17 saccharide heparin

16

Fondaparinux MOA

pentasaccharide heparin

17

Pharmacokinetics of heparin

immediate onset
parenteral
"sticky," must monitor aPTT
LMWH/fondaparinux- don't need to monitor aPTT

18

Selectivity of heparins

Heparin inactivates thrombin and Xa
LMWH inactivates Xa well, thrombin poorly
Fondaparinux inactivates Xa only

19

Therapeutic use of heparin

initial treatment of DVT/PE
transition to warfarin
safe in pregnancy

20

Adverse effects of heparin

bleeding, protamine sulfate antidote
HIT/HITT - CBC needed

21

Alternative anticoagulants in HIT

bivalirudin, fondaparinux

22

Vitamin K antagonist

warfarin

23

MOA of warfarin

inhibits synthesis of K-dependent clotting factors by inhibiting VKOR1C in the liver

24

Pharmacokinetics of warfarin

oral
delayed onset, dependent on clotting factor turnover
metabolized by CYP2C9

25

Dosing of warfarin

must be monitored by PT/INR

26

Therapeutic use of warfarin

prevent progression of recurrence of DVT or PE
Prevention of thromboembolism in patient with prosthetic heart valves
not useful in an emergency

27

Adverse effects of warfarin

boxed warning for bleeding
antidote is vitamin K, takes hours, for immediate need- prothrombin complex concentrate (PPC) or plasma.
Teratogen

28

Drug interactions with warfarin

CYP inhibitors
displacement of plasma albumin
broad spectrum antibiotics
anything that promotes bleeding

Reduce warfarin effect
CYP inducers
excessive vitamin K

29

Direct inhibitors of thrombin

bivalirudin- parenteral
dabigatran etexilate- oral

30

bivalirudin MOA

binds to and inhibits thrombin

31

Pharmacokinetics of bivalirudin

given IV and monitored by aPTT, short half life, excreted by the kidney

32

Therapeutic use of bivalirudin

used for HITT and during PCI

33

Adverse effect of bivalirudin

bleeding

34

Pharmacokinetics of dabigatran etexilate

orally active
onset 2-3 hrs
dosed 2x per day without monitoring

35

Therapeutic use of dabigatran

"warfarin replacement"
no monitoring required

36

Adverse effect of dabigatran

bleeding with no antidote

37

Thrombolytic agents

t-PA

38

MOA of t-PA

activates plasminogen and breaks up fibrinogen clot.

39

Therapeutic use of t-PA

within the first three hours after MI