Warfarin

Question 1

What type of drug is warfarin?

Answer 1

oral anticoagulant

Question 2

What does warfarin inhibit?

Answer 2

epoxide reductase preventing reduction of vitamin K to its active hydroquinone form

Question 3

Which clotting factors is warfarin a cofactor for the carboxylation of?

Answer 3

10, 9, 7, 2 (1972) and protein C

Question 4

What factors may increase the function of warfarin?

Answer 4

• liver disease
• P450 enzyme inhibitorzz (amiodarone, ciprofloxacin)
• cranberry juice
• drugs that displace warfarin from plasma albumin (NSAIDs)
• inhibit platelet function (NSAIDs)

Question 5

What are the side effects?

Answer 5

• haemorrhage
• tetrogenic
• skin necrosis
• purple toes