A patient on warfarin for atrial fibrillation presents with severe bruising and haematuria. What is the most appropriate immediate action?

• A. Stop the warfarin immediately
• B. Hold warfarin and seek guidance
• C. Switch to heparin suddenly
• D. Take vitamin K and resume later

Answer: (A)

When major bleeding occurs on warfarin, stopping the drug immediately is the priority because warfarin’s effect on reducing vitamin K–dependent clotting factors allows bleeding to continue. Halting warfarin removes the source of anticoagulation right away, which is essential to control the bleed. In practice, this would be followed by reversing anticoagulation (often with IV vitamin K and rapid factor replacement such as PCC or FFP) and then reassessing when and how to resume anticoagulation. Switching to heparin would worsen the bleeding in the active bleed, and waiting to seek guidance delays reversal, which could be dangerous.