Warfarin

Question 1

Major bleeding

Answer 1

Stop warfarin

Give IV Vit K 5mg

Prothrombin complex concentrate, if not available then FFP

Question 2

INR over 8

Minor bleeding

Answer 2

Stop warfarin

Give IV Vit K 1-3mg

Repeat dose of Vit K if INR still too high 24hrs later

Restart warfarin when INR under 5

Question 3

INR over 8

No bleeding

Answer 3

Stop warfarin

Give Vit K 1-5mg orally

Repeat dose if INR still too high 24hrs later

Restart when INR under 5

Question 4

INR 5-8

Minor bleeding

Answer 4

Stop warfarin

Give IV Vit K 1-3mg

Restart when INR under 5

Question 5

INR 5-8

No bleeding

Answer 5

Withhold 1 or 2 doses

Reduce subsequent maintenance dose

Question 6

Target INR for venous thromboembolism

Answer 6

2.5

Recurrent 3.5

Question 7

Target INR for AF

Answer 7

2.5

Question 8

Warfarin affects

Answer 8

Prothrombin Time

X, IX, VII, II (1972) and protein C

Question 9

What interacts with warfarin

Answer 9

Green veg - high in Vit K

Question 10

Things that potentiate warfarin

Answer 10

Liver disease
P450 enzyme inhibitors
Cranberry juice
NSAIDs