So, today we are discussing about factor Xa Inhibitors and why they are preferred over old , classic warfarin.

  • As name suggest these drugs directly inhibit factor Xa (important factor of coagulation cascade in common pathway)
  • Examples are- Rivaroxaban and Apixaben

They have several advantages over warfarin like

  1. They act rapidly and have short lasting action (unlike warfarin which act through inhibiting synthesis of vitamin K dependent clotting factors, so having a lag time, as the preformed clotting factors have to cleared off the bloodstream first)
  2. Lower risk of bleeding as compared to warfarin hence..
  3. No laboratory monitoring is required (unlike oral warfarin where INR has to be measured daily (initially) and later weekly)
  4. Equally effective as anticoagulant compared to warfarin .
  5. Very few drug interactions (we know that warfarin is metabolized by CYP2C9 and CYP3A4, and are 99% plasma protein bound, hence warfarin is liable to more drug interactions)
  6. Clear guidelines regarding dosage as per indications (where warfarin is required frequent laboratory monitoring and dose adjustments)

So, no surprise that these drugs have gained popularity.

They are used for :-

A. Prophylaxis of Deep vein thrombosis/Pulmonary embolism after knee/hip replacement, high risk bed ridden patients.

B. Treatment of Deep vein thrombosis/Pulmonary embolism

C. For prophylaxis of stroke /systemic embolism in patients of nonvalvular Atrial Fibrillation

Hope you enjoyed the concept ……..