Warfarin

Question 1

Class

Answer 1

Vitamin K Antagonist

Question 2

Mechanism

Answer 2

• Vitamin K epoxide reductase inhibitor -> depletes Vit K dependent coagulation factors (X,IX,VII,II) -> Anticoaggulation

N.B. Delayed onset

(No need to monitor INR with DOAC)

Question 3

Indications

Answer 3

• Prophylaxis of thrombotic events (i.e. prosthetic valve, RHD)

Question 4

SE

Answer 4

Common: Haemorrhage

Important: Skin necrosis, hypersensitivity, liver dysfunction, jaundice, pyrexia

Question 5

CI

Answer 5

• Severe renal impairment, pregnancy, liver disease, HTN

Question 6

Monitoring

Answer 6

• INR checked (this is ratio of the patient’s prothrombin time:reference standard blood prothrombin time)
  
  • <1.5 dangerous
    
    • Everyday at the start of Tx.

Question 7

Antidote

Answer 7

Vit K, FFP