Anticoagulation

Question 1

Heparin MOA

Answer 1

Potentiates antithrombin → decreased transformation of prothrombin to thrombin

Question 2

Heparin Route of Administration

Answer 2

SQ (prophylaxis) or IV Continuous Infusion (treatment)

Question 3

Heparin Half-Life

Answer 3

1-2 hours (IV)

Question 4

Heparin Monitoring (efficacy)

Answer 4

Either Anti-Xa levels (~0.3-0.7 units/mL) or aPTT levels (ranges vary per lab) need to be within therapeutic range

Question 5

Low molecular weight hearpin (LMWH) MOA

Answer 5

Potentiates antithrombin → decreased transformation of prothrombin to thrombin AND inactivates factor Xa

Question 6

Examples of LMWH

Answer 6

Enoxaparin (Lovenox)
Dalteparin (Fragmin)

Question 7

LMWH Route of Administration

Answer 7

SQ (rarely can be given IV)

Question 8

LMWH Half-Life

Answer 8

~12 hours

Question 9

LMWH Dose Adjustments

Answer 9

CrCl < 30 mL/min

Question 10

LMWH Efficacy Monitoring

Answer 10

Anti-Xa levels only in specific populations - obese, renal dysfunction, pregnant

Question 11

List the Direct acting oral anticoagulants

Answer 11

Apixaban (Eliquis), Rivaroxaban (Xarelto), Edoxaban (Savasya), Dabigatran (Pradaxa)

Question 12

List Factor-Xa inhibitors

Answer 12

Apixaban (Eliquis), Rivaroxaban (Xarelto), Edoxaban (Savasya), Fondaparinux (Arixtra)

Question 13

List Factor IIa inhibitors (direct thrombin inhibitors)

Answer 13

Dabigatran (Pradaxa) (Direct thrombin inhibitor)

Question 14

Warfarin indications

Answer 14

1. Valvular Afib
2. Mechanical heart valves
3. Some hypercoagulable states

Question 15

Warfarin MOA

Answer 15

Vitamin K antagonist->decreases hepatic synthesis of factors 2,7,9, and 10, protein C and S by blocking carboxylation

Question 16

Warfarin route of administration

Answer 16

Oral

Question 17

Warfarin half-life

Answer 17

20-60 hours~

Question 18

Warfarin DDI

Answer 18

• CYP1A2, CYP2C19, and MAJOR (CYP2C9 and (CYP3A4)
• Amiodarone
• Macrolide Antibiotics (Azithromycin, Erythromycin)
• -azole antifungals (fluconazole)
• Sulfa antibiotics (Bactrim)
• Rifampin

Question 19

Warfarin monitoring parameters

Answer 19

INR 2-3 (1 considered normal)
Hgb, Hct, platelets

Question 20

What is the brand name of Apixaban?

Answer 20

Eliquis

Question 21

Apixaban route of administration

Answer 21

oral

Question 22

Apixaban AFib Dosing

Answer 22

5 mg twice daily

Question 23

Apixaban VTE Dosing

Answer 23

10mg twice daily x 1 week, then 5 mg twice daily

Question 24

Apixaban dose adjustment

Answer 24

AFib:

2. 5mg BID if 2/3 criteria are met:
3. SCr > 1.5
4. Weight < 60 kg
5. Age > 80 years old

Question 25

Apixaban DDI

Answer 25

Major substrate of CYP3A4

Question 26

Rivaroxaban brand name

Answer 26

Xarelto

Question 27

Rivaroxaban route of administration

Answer 27

PO

Question 28

Rivaroxaban AFib Dosing

Answer 28

20 mg daily WITH FOOD

Question 29

Rivaroxaban VTE Dosing

Answer 29

15 mg twice daily x 21 days then 20 mg daily WITH FOOD

Question 30

Rivaroxaban dose adjustment

Answer 30

Afib Only: CrCl 15-50 mL/min then 15 mg daily with food Avoid use CrCl \< 15 mL/min

Question 31

Rivaroxaban DDI

Answer 31

Major substrate of CYP3A4

Question 32

Brand name of Edoxaban

Answer 32

Savaysa

Question 33

Edoxaban route of administration

Answer 33

Oral

Question 34

Edoxaban dose AFIB

Answer 34

60 mg PO QD

Question 35

Edoxaban dose in VTE

Answer 35

After 5 days of parenteral anticoagulation: \>60kg = 60 mg PO QD ≤60kg = 30 mg PO QD

Question 36

Edoxaban renal dose adjustment

Answer 36

AFIB: 15-50 ml/min: 30 mg PO QD

Question 37

Edoxaban use caveat (Renal)

Answer 37

Only use in patients with moderate kidney function CrCl 15-95 ml/min

Question 38

Fondaparinux brand name

Answer 38

Arixtra

Question 39

Fondaparinux route of administration

Answer 39

Parenteral: SQ and IV

Question 40

Avoid fondaparinux in these populations

Answer 40

CrCl \< 30 mL/min Weight \< 50 kg

Question 41

Dabigatran route of administration

Answer 41

Oral

Question 42

Dabigatran AFib Dosing

Answer 42

150 mg twice daily

Question 43

Dabigatran VTE Dosing

Answer 43

5 days parenteral then 150 mg twice daily

Question 44

Dabigatran renal adjustment

Answer 44

Afib: CrCl 15-29 mL/min 75 mg twice daily Avoid CrCl \< 15 mL/min VTE: Avoid CrCl \< 30 mL/min

Question 45

Dabigatran weight consideration

Answer 45

Avoid \> 120 kg, BMI ≥ 40 kg/m2

Question 46

Bivalirudin MOA

Answer 46

Direct thrombin inhibitor

Question 47

Bivalirudin route of administration

Answer 47

Continuous IV infusion

Question 48

Bivalirudin half-life

Answer 48

10-24 minutes

Question 49

Argatroban MOA

Answer 49

Direct Thrombin Inhibitor

Question 50

Argatroban Route of Administration

Answer 50

Continuous IV Infusion

Question 51

Argatroban Half-Life

Answer 51

39-51 minutes

Question 52

Heparin-Induced Thrombocytopenia (HIT) Risk Factors

Answer 52

1. Source: Bovine > Porcine 2. UFH > LMWH 3. IV > SQ 4. Surgical patients > Medical/Obstetric 5. Longer exposure = higher risk

Question 53

4T Score Components

Answer 53

1. Thrombocytopenia 2. Timing 3. Thrombosis 4. Other Cause

Question 54

HIT is an indication for therapeutic anticoagulation (T/F)

Answer 54

TRUE!