Factor Xa Inhibitor

Question 1

What are examples of Factor Xa inhibitors?

Answer 1

• Rivaroxiban
• Apixiban
• Edoxiban
• Fondaparinux

Question 2

What are indications for factor Xa inhibitors?

Answer 2

• Prophylaxis of thromboembolism following surgery
• Initial and continued treatment of DVT/PE
• Prophylaxis of thromboembolic events

Fondaparinux Only:

• Treatment NSTEMI and STEMI and ustable angina
• Also be used to treat HIT

Question 3

What are contraindications to Factor Xa inhibitor use?

Answer 3

• Active bleeding
• Bacterial Endocarditis (fondaparinux only)
• Recent surgery
• Recent brain or spinal cord injury
• Vascular aneurysms
• GI ulceration
• Hepatic Disease
• Oesophageal varices
• Pregnancy and breastfeeding

Question 4

What is the mechanism of action of factor Xa inhibitors?

Answer 4

Factor Xa amplifies coagulation by converting prothrombin to thrombin in response to injury. Direct inhibitors (rivaroxaban, apixaban) block the active site of the factor Xa molecule.
Fondaparinux is an indirect inhibitor and works by enhancing the ability of antithrombin to neutralise Factor Xa.

Question 5

What are adverse reactions of Factor Xa inhibitors?

Answer 5

• Anaemia
• Bleeding
• Purpura
• Haemorrhage
• Epistaxis (edoxaban)
• GI upset (rivaroxaban)

Question 6

How are DOACs administered?

Answer 6

Sitting upright with glass of water

Question 7

How are DOACs taken?

Answer 7

Once/Twice daily tablet/capsule

Question 8

What shluld you advise people to look out for when starting them on DOACs?

Answer 8

Bleeding - head injury, nosebleed, GU/GI bleeding, unusual headaches, black stool, severe bruising

Question 9

What would you check before starting someone on a DOAC?

Answer 9

Renal impairment - U+E’s