Injectable Factor Xa Inhibitors (FXa) and Direct Thrombin Inhibitors (DTI)

Question 1

What is the injectable factor Xa inhibitor?

Answer 1

Fondaparinux

Question 2

What are the labeled uses of Fondaparinux?

Answer 2

-Prophylaxis following THA, TKA, hip replacement, or abdominal surgery
-Treatment of DVT or PE

Question 3

Would Fondaparinux be defined as a streamlined dosing regimen or a variable dosing regimen?

Answer 3

-Fondaparinux is streamlined meaning that it does not needed to be titrated or adjusted
-FYI: for treatment, it is weight-based and for prophylactic use, it is 3.5mg subq once daily

Question 4

Fondaparinux considerations

Answer 4

-Do not use if have renal dysfunction (CrCl <30 mL/min)
-Do not use for prophylaxis with low body weight (<50kg)
-Can be used in HIT (preferred because there is no routine monitoring)
-No routine monitoring for therapeutic efficacy (can be monitored but not recommended)
-Safe to use in pregnancy

Question 5

What are the IV direct thrombin inhibitors?

Answer 5

-Lepirudin
-Bivalirudin (Angiomax)
-Argatroban

Question 6

What indicated use do all IV direct thrombin inhibitors have in common?

Answer 6

HIT

Question 7

What are some special considerations regarding Argatroban?

Answer 7

-Dose must be lowered with hepatic impairment
-Elevates INR, so overlap with Warfarin until INR is 4 or greater , then once INR reaches 4, d/c Argatroban and continue Warfarin