Editing Anticoagulation (section)

== '''Warfarin''' ==

* Vitamin K epoxide reductase inhibitor - competitively inhibits the hepatic synthesis of the vitamin K-dependent clotting factors II, VII, IX, X
* Can be reversed by simply replacing those factors with FFP or prothrombinex, and giving supplemental vitamin K to overcome the inhibition
* FFP only leads to a median reduction of INR of 0.2. Also, it can't be administered quickly, and you need a large volume.
* Prothrombinex - generally three-factor, containing II, IX and X; but some four-complex versions are available - can be rapidly reconstituted and reversed from its stored powder form. The volume is <100mL. The main disadvantage is cost. INR <1.3 at 30 minutes from start of treatment was achieved in 62% of prothrombinex group but only 10% of FFP group.
** Three-factor prothrombinex is fine for INR <4, but it has been suggested that four-factor should be used when INR >4, or three-factor + FFP.
* Vitamin K IV results in a lower INR 4-6 hours after infusion (5-10mg diluted in 50mL N/S and given over 20 minutes)
* Prothrombinex doses

{| class="wikitable"
|Initial INR
|1.5-2.5
|2.6-3.5
|3.6-10
|>10
|-
|Target INR 0.9-1.3
|30IU/kg
|35IU/kg
|50IU/kg
|50IU/kg
|-
|Target INR 1.4-2.0
|15IU/kg
|25IU/kg
|30IU/kg
|40IU/kg
|}