Warfarin

Question 1

what type of drug is warfarin

Answer 1

vitamin K antagonist

Question 2

production of what factors is reduced by warfarin

Answer 2

2
7
9
10

+ protein C and protein S

Question 3

what pathway of the clotting cascade does warfarin work on

Answer 3

extrinsic

Question 4

why is heparin often given alongside warfarin in the first few days of treatment

Answer 4

on starting warfarin there is a delay to the peak time of action becuase factor depletion takes several days

Question 5

what does the INR use

Answer 5

prothrombin time

Question 6

give some rough target INRs

Answer 6

normal 1

target 2-3

Question 7

what two drugs might decrease the effect of warfarin

Answer 7

rifampicin

anti-epileptics

Question 8

what system metabolises warfarin

Answer 8

cytochrome p450

Question 9

give three things that might potentiate the effect of warfarin

Answer 9

omeprazole
erythromycin
cranberry juice

Question 10

if there is a serious bleed and the patient is on warfarin what should you do

Answer 10

1. stop warfarin
   IV vitamin K
   prothrombin complex concentrate eg. beriplex

Question 11

what can you do to reverse warfarin

Answer 11

prothrombin complex concentrate eg. beriplex