Coagulation

Question 1

Factor Xa inhibitor examples

Answer 1

Rivaroxaban (Xarelto)
Apixaban (Eliquis)
Endoxaban (Savaysa)
Betrixaban (Bevyxxa)

Question 2

Warfarin (Coumadin)

MOA

Answer 2

inhibits synthesis of vitamin K–dependent clotting factors X, IX, VII, and II (prothrombin)

Question 3

Heparin MOA

Answer 3

Binds with antithrombin III

Inactivates factors IXa, Xa, XIIa, XIII

Question 4

LMWH MOA

Answer 4

Inactivates factor Xa

Question 5

Bridging from heparin/LMH is necessary with which drug?

Answer 5

warfarin, not necessary with DOACs

Question 6

Warfarin precautions and contraindications

Answer 6

Pregnancy category X
Use cautiously in patients with fall risk, dementia, or uncontrolled hypertension
Avoid in hypermetabolic state

Question 7

Warfarin Antidote

Answer 7

vitamin K

Question 8

General warfarin dosing guidelines

Answer 8

Increase (if INR low) or decrease (if INR) high weekly dose by 10%

Question 9

INR goals for patients with:

1. Afib/thromboembolism
2. Mechanical Heart Valve

Answer 9

1. 2.0-3.0

2. 2.5-3.5

Question 10

Warfarin initiation

Answer 10

Start at 5 mg per day

Start at 2.5mg if <110 lbs or >age 75

Question 11

Warfarin is the only anticoagulant indicated for what condition?

Answer 11

Mechanical Heart Valves (DOACs not approved)

Question 12

DOAC cautions

Answer 12

renal insufficiency/failure

Question 13

DOAC pros/cons as compared to warfarin

Answer 13

• no monitoring required - saves patients time but no way to monitor compliance
• shorter half life - out of the system faster in case of bleeding but missing a dose is risky
• more expensive out of pocket to the patient, may be cheaper to healthcare system in general due to less monitoring/adverse effects
• fewer drug/food interactions

Question 14

DOAC Antidotes

Answer 14

Thrombin Inhibitors: Praxbind
Factor Xa inhibitors: Andexxa

These are expensive and used only in emergency settings - often time will take care of bleeding due to short half life

Question 15

Oral Direct Thrombin Inhibitors example

Answer 15

Dabigatran (Pradaxa)

Question 16

dabigatrain monitoring

Answer 16

none

Question 17

ASA MOA and how long to efffects last

Answer 17

binding irreversibly to the enzyme cyclooxygenase in platelets, which inhibits the formation of thromboxane A2, a powerful inducer of platelet aggregation.

**Effects may persist up to a week.

Question 18

ASA indication

Answer 18

primary/secondary prevention of stroke & MI

Question 19

Adenosine diphosphate (ADP) receptor blockers – Examples

Answer 19

Ticlopidine & Clopidogrel (examples)

Question 20

Adenosine diphosphate (ADP) receptor blockers – MOA

Answer 20

irreversibly block the ADP receptors, altering the plasma membrane of platelets.

Question 21

Glycoprotein IIb/IIIa receptor antagonists
examples
(*were reviewed in lecture)

Answer 21

abciximab*
tirofiban
eptifibatide

Question 22

Glycoprotein IIb/IIIa receptor antagonists - Indication

Answer 22

prevent thrombi in recent MI, stroke or PCI

Question 23

ADP receptor blockers indications

Answer 23

Secondary prevention of stroke, MI, PVD

Superior to aspirin alone in prevention of these

Question 24

Ideal “door to needle” time with tPA

Answer 24

<60 min

must be administered within 3 hours of stroke symptoms onset

Question 25

Anticoagulant preferred in pregnancy

Answer 25

LMWH