Sketchy Pharm: Warfarin

Question 1

What enzyme is blocked by warfarin?

Answer 1

Vitamin K epoxide reductase

Question 2

Vitamin K aids in the _____________ of factors II, VII, IX, X, C and S.

Answer 2

gamma-carboxylation of glutamic acid residues

Question 3

What are Sketchy’s symbols for factors VII and IX?

Answer 3

VII: devil (for the seven deadly sins)
IX: cat (for nine lives)

Question 4

Why is vitamin K epoxide reductase necessary?

Answer 4

Because when vitamin K assists in the gamma-carboxylation of the clotting factors it gets converted to epoxide. It needs to be reduced back to its active form in order to keep reactivating the clotting factors.

Question 5

What timeline does warfarin work on?

Answer 5

It starts to work in 8 to 13 hours, but doesn’t achieve its full effect for roughly three days.

Question 6

Factor _______ is the first clotting factor to be inactivated by warfarin. (This is part of why PT is used to monitor warfarin levels.)

Answer 6

VII (think of the injured soldier –the first one down –wearing the devil symbol on his helmet)

Question 7

What INR is recommended for therapeutic prevention of clots?

Answer 7

2-3 (just like the ParaTrooper with his INtercom Radio set to 2.5)

Question 8

Warfarin should never be used in __________.

Answer 8

pregnant women

Question 9

Warfarin-induced skin necrosis comes from ___________.

Answer 9

knockout of protein C (neCCCCrosis)

Question 10

What two treatments are needed for warfarin overdose?

Answer 10

Vitamin K (which has a delayed effect) and fresh-frozen plasma (which has an immediate effect)