Other Anti-coags

Question 1

Factor Xa inhibitors (oral), MOA

Answer 1

• Rivaroxaban
• Edoxaban
• Apixaban

-MOA: oral direct factor Xa inhibitor (inhibits free and clot-bound factor Xa)

Question 2

Clinical indications of factor Xa

Answer 2

• Prevention of VTE in pts undergoing THA/TKA (tx for at least 10-14d, preferably 35d)
• Prevention of stroke/systemic embolism in pts with non-valvular AF
• Prevention and tx of VTE

Question 3

Clinical indication for Rivaroxaban

Answer 3

PAD

Question 4

When should you start the oral factor Xa inhibitors? How’s the bleeding risk?

Answer 4

• Start after surgery

- Bleeding risk LESS than warfarin (apixaban has the least)

Question 5

What is the reversal agent for the oral Xa inhibitors?

Answer 5

Andexanet-alpha

Question 6

Drug interactions for oral Xa inhibitors

Answer 6

• Most are substrates of P-GP and 3A4

- Don’t use with other anticoags

Question 7

LMWH drug and MOA

Answer 7

• Enoxaparin

- MOA: antithrombin mediated inhibition of factors Xa > IIa

Question 8

LMWH clinical indications

Answer 8

-DVT prophylaxis of hip/knee/abd sxs, restricted mobility
-DVT/PE tx
-ACS
(use this unless you can’t, lots of advantages)

Question 9

What is a limitation of LMWH?

Answer 9

Harder to dose in CKD and obese pts

Question 10

Drug monitoring for LMWH

Answer 10

• Monitor for anemia/signs of bleeding (H/H)

- No anticoag monitoring necessary, best during tx rather than prophylaxis

Question 11

What is the reversal agent for LMWH?

Answer 11

Protamine sulfate

Question 12

Common ADRs of LMWH

Answer 12

• Injection site pain and hematoma
• Hemorrhage less than UFH
• Thrombocytopenia < UFH
• HIT rarely (<1%)

Question 13

Synthetic analog of Heparin, MOA

Answer 13

Fondaparinux, anti-thrombin mediated inhibition of factor Xa

Question 14

Clinical indications of Fondaparinux

Answer 14

• DVT prophylaxis of hip/knee/abd sxs

- VTE tx

Question 15

What is a unique advantage of Fondaparinux?

Answer 15

Long half life (qd dosing)

Question 16

What is the drug monitoring, drug interactions, and ADRs to be aware of in Fondaparinux?

Answer 16

• Monitor: H/H, SCr, anti-Xa assay
• Interactions: other antiplatelets/anticoags/NSAIDs -> bleeding
• ADRs: hemorrhage

Question 17

What are the direct thrombin inhibitors (oral, IV)

Answer 17

• Oral: Dabigatran

- IV: Argatroban, Bivalirudin

Question 18

MOA of Dabigatran

Answer 18

Synthetic, non-peptide, direct thrombin (IIa) inhibitor, inhibits both clot bound and circulating thrombin -> decreases thrombin-stimulated platelet aggregation

Question 19

Clinical indications of Dabigatran

Answer 19

• Prevention of stroke in pts with non-valvular AF
• Prevention of VTE in pts undergoing THA/TKA
• VTE tx (not initial)

Question 20

What is the reversal agent for Dabigatran?

Answer 20

Idarucizumab

Question 21

What is a unique pearl about the storage of Dabigatran?

Answer 21

Sensitive to moisture, should be kept in original bottle and tightly capped

Question 22

Dabigatran + __________ = increase hemorrhage

Answer 22

Simvastatin

Question 23

ADRs of Dabigatran

Answer 23

• Bleeding

- Dyspepsia/gastritis

Question 24

What is the only approved product for pts with HIT?

Answer 24

Argatroban

Question 25

Argatroban has a very short half life and is safest in a patient with what?

Answer 25

CKD, metabolized by the liver

Question 26

Bivalirudin pearls

Answer 26

• Approved for ACS managed with PCI
• Pts with/at risk of HIT undergoing PCI
• Cannot reverse

Question 27

Old fibrinolytics

Answer 27

• Streptokinase

- Urokinase

Question 28

Older fibrinolytic, MOA

Answer 28

• Alteplase aka recombinant tissue-type plasminogen activator (tPA)
• MOA: initiates local fibrinolysis by binding to fibrin in a thrombus, converts entrapped plasminogen to plasmin

Question 29

Clinical indications of alteplase

Answer 29

• STEMI
• Acute pulm embolism
• Acute ischemic stroke
• Central venous cath clearance
• Acute peripheral arterial occlusive disease

Question 30

Newer fibrinolytic, MOA

Answer 30

• Tenecteplase
• 14x more fibrin specific
• MOA: same as alteplase with longer half life (single IV bolus)

Question 31

Clinical indications of Tenecteplase

Answer 31

STEMI

Question 32

Warfarin, UFH, LMWH in pregnancy

Answer 32

• Warfarin: crosses placenta, teratogenic
• UFH: cat C (no known teratogenecity, does not cross placenta)
• LMWH: enoxaparin is cat B for VTE

Question 33

Warfarin embryopathy is characterized by:

Answer 33

• Midface hypoplasia
• Stippled chondral calcification
• Scoliosis
• Short proximal limbs/phalanges