Anticoagulants: vit K antagonists Flashcards Preview

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Flashcards in Anticoagulants: vit K antagonists Deck (45):
1

What is the first MOA of warfarin

Inhibits post-translational carboxylation of coag factors II (protrombin), VII, IX, and X

2

What is the 2nd MOA of warfarin

Inhibits 2 vit-k sensitive synthetic enzymes

3

How is warfarin reversed?

Pharmacological doses of Vit K

4

What is the Vit K agent used to reverse warfarin?

Phytonadione

5

What is the risk with IV phyotonadion?

Rare risk of anaphylaxis with rapid infusion

6

How do you start warfarin?

With heparin in cases of A-fib, DVT, PE

7

How long does it take warfarin to provide full anticoagulation?

5-7 days

8

How do you measure warfarin effects?

With prothrombin time (PT) and international normalized ration (INR)

9

What is the therapeutic INR range for AFib, DVT, PE?

2-3

10

What is the therapeutic INR range for mechanical heart valves?

2.5-3.5
*not porcine*

11

How long does it take a dose of warfarin to become effective?

48 hours

12

What is a complication of starting 10 mg of warfarin daily?

Warfarin induced skin necrosis

13

What drug interaction can cause increased risk of bleeding with warfarin and what do they do to the INR?

Drugs that inhibit CYP2C9
Increase INR

14

What drugs inhibit CYP2C9 and negatively interact with warfarin?

Bactrim
Flagyl

15

What drug interaction can cause increase risk of thrombosis with warfarin and what do they do to the INR?

Drugs that induce CYP2C9
Decrease the INR

16

What drugs induce CYP2C9 and negatively interact with warfarin?

Contraceptives

17

What are some sources of high dietary folate

Beef
Pork liver
Green teas
Leafy green vegetables
Spinach

18

Supratherapeutic INR treatments

See slide 47

19

What is an example of an anti-factor XA inhibitor and how does it come?

Fondaparinux
Pre-filled syringes

20

What is fondaparinux?

Synthetic pentasaccharide

21

How is fondaparinux eliminated?

Mainly renally

22

When is fondaparinux contraindicated?

CrCL<30

23

What is an unlabled use of fondaparinux?

DVT prophylaxis in pts w/ a h/o HIT

24

What is Rivaroxaban (Xarelto)?

An oral direct Xa inhibitor

25

What is a benefit of Rivaroxaban?

No lab monitoring

26

What is the reversal agent of Rivaroxaban?

Andexanet alfa

27

What is the MC adverse effect of rivaroxaban?

Bleeding
> 5%

28

What are some examples of bivalent direct thrombin inhibitors (DTIs)

Lepirudin
Bivalrudin
Desirudin

29

What are some examples of univalent DTIs

Argatroban
Dabigatran

30

What is an advantage of DTIs

They can be used in pts w/ h/o HIT-II

31

What is argatroban used for?

To treat HIT

32

How is argatroban given and how is it monitored?

IV
Monitored w/ PTT

33

What is an advantage of argatroban?

It is not renally eleminated so it can be used in pts w/ HIT and poor renal fxn

34

Which drug was withdrawn by AstraZenaca in 2006?

Ximelagatran

35

What DTI is given orally?

Dabigatran

36

What lab testing does dabigatran require?

None :D

37

Does dabigatran have a reversal agent?

Yes!
FDA approved 2015

38

What is the dabigatran reversal agent?

Idarucizumab

39

What is idarucizumab?

Human monoclonal antibody

40

What is the MOA of idarucizumab?

It binds to pradaxa

41

How do you deliver idarucizumab?

Two consecutive 2.5 gram doses IV

42

What is a negative of idarucizumab?

$3500 for 1 dose

43

What is andexanet alfa?

A factor xa decoy protein
*factor Xa inhibitor reversal agent*

44

What drugs does andexanet alfa correct?

Apixaban
Rivaroxaban
Edoxaban
Enoxaparin
Fondaparinux

45

What are the doses of phytonadione?

2.5-10 mg po (5 mg tablet)
1-10 mg IVPB