anti coag drugs Flashcards
heparin, what does it potentiate?
ATIII, immediate effect
unfractioned binds?
thrombin
LMWH binds?
factor xa
heparin potentiates anti thrombin III
either binds xa or thrombin
how do you monitor unfractioned?
APTT
LMWH?
don’t usually need to monitor
complications?
heparin induced thrombocytopaenia (low platelets)
osteoperosis in very long use
to reverse heparin?
usually just stop
occasionally in severe bleeding, what can you give?
protamine sulphate
what is the effect of protamine sulphate on unfractioned heparin and LMWH
complete reversal for unfractioned, partial reversal for LMWH
how does warfarin work?
inhibits vitamin K
what does vitamin K do to factors 2,7,9,10?
carboxylates them
where are clotting factors produced?
liver
antagonism of vitamin K
y
when should dose be taken?
same time every day
how long does it take to get the full effect of warfarin?
3-5 days
may need what to cover this period?
heparin
what is prothrombin time?
patients pt in seconds/mean normal pt in seconds to the power of international sensitivity index
warfarin - beware of drug interactions!!!
y
skin bruising, epistaxis, haematuria
severe - gastrointestinal, intracerebral, significant drop in hb
warfarin reversal - pathway?
no action - omit dose - administer oral vitamin K, administer clotting factors
how long does vitamin k take to work?
6 hours
clotting factors?
immediate effect
what is factor 2?
prothrombin
heparin - what can it do to platelets and bone?
causes thrombocytopenia and long term use can cause osteoporosis
how can obstructive jaundice cause bleeds?
bile salts are needed to absorb vitamin K in the upper intestine. Vitamin K carboxylises prothrombin, 7,9 and 10
to reverse warfarin, what are the steps?
do nothing –> omit warfarin dose –> give vitamin K –> give activated clotting factors
how long does administered vitamin K take to work?
6 hours
how long does activated clotting factor take to work
immediate effect
what is dabigatran?
thrombin inhibitor
name two factor Xa inhibitors?
rivaroxaban and apixaban
in arterial clots, what do platelets release that cause further aggregation?
thromboxane A2
HOW DO YOU MONITOR PATIENTS ON HEPARIN?
fbc (thrombocytopenia and osteoporosis)
what does heparin help?
helps anti thrombin III bind to thrombin and factor 10 a
most common thrombophilia?
factor V leidig
