Warfarin

Question 1

Class

Answer 1

Anticoagulant

Question 2

MoA

Answer 2

Vit K antagonist - thins blood to prevent blood clots
Blocks vitamin K - used in body to make proteins that cause the blood to clot

Question 3

Treatment course and how it’s taken

Answer 3

OD tablet (usually in eve)
- DVT - 3 months
- PE - 6 months
- AF - lifelong

Question 4

How long do wardarin dose changes take to take effect?

Answer 4

2-3 days

Question 5

Contraindications

Answer 5

Pregnancy
Significant risk of major bleeding
Active bleeding

Question 6

Monitoring

Answer 6

• 5mg each evening
• INR on days 3, 4 and 5 - warfarin dosing charts will tell you how to adjust dose
• Then regular INR checks by anticoagulation clinic – regularity determined by INR stability (patient will be given anticoagulation book)

Question 7

Side effects

Answer 7

– Bleeding
– Also diarrhoea, rash, hair loss, nausea

Question 8

Interactions

Answer 8

Many interactions (mostly with P450 cytochrome inducers/inhibitors) – patients should avoid liver, spinach, cranberry juice, alcohol binges, NSAIDs/aspirin

Question 9

Safety netting

Answer 9

seek medical advice if you have a significant head injury, prolonged nose bleeds, unusual headaches, blood in urine/stool/vomit, black stool, unexplained or severe bruising

Question 10

What to do if you miss a dose

Answer 10

DON’T DOUBLE DOSE
Either take later in day, or wait until next scheduled dose