Warfarin

Question 1

what is it and mechanism

Answer 1

Oral anticoagulant (not a DOAC)

blocks vitamin K enzyme which inhibits factors 2,7,9 and 10 hence stopping the coagulation cascade

Question 2

indications

Answer 2

prophylaxis of DVT/PE in rheumatic heart disease or AF (first line)

after insertion of heart valves

treatment of DVT/ PE

TIA

Question 3

contraindications

Answer 3

pregnancy in first and third trimester ( i.e. only in the second)

stroke

bleeding

within 72 hours of surgery with risk of bleeding

postpartum 48 hours

Question 4

interactions

Answer 4

any drug which has an effect on bleeding

fibrinolytic drugs e.g. TPA (alteplase)

NSAIDs

SSRIs

a lot of antibiotics

statins

Question 5

side effects

Answer 5

haemorrhage

mild rash

hair loss