Anticoags Flashcards
venous thrombotic events
dvt
pe
arterial thrombotic events
coronary
cerebral
peripheral
indications for anti coags
venous thrombosis
afib
MOA of heparin
potentiates anti thrombin
enhances effect of it (inhibits clotting factors)
binds to thrombin/ factor 10, complex switches it off, heparin wraps around and keeps it secure so they dont associate again
LMWH and unfractioned-
how long does heparin take to act
immediate efffect
how to monitor heparin
activated partial thromboplastin time for unfractioned
anti-xa assay for LMWH but usually not required to monitor lmwh as more predictable response
complications of heparin
bleeding
heparin induced thrombocytopenia - monitor FBC
what can heparin cause long term
osteoporosis
what to do if a patient is bleeding on heparin
stop the heparin
gone out the ssystem within 30 minutes usually
what does unfractioned heparin inhibit
factor xa and and thrombin
what does lmwh inhibit
greater effect on factor xa than on thrombin
coumarin anticoags
warfarin
phenindione
acenocoumarin
phenprocoumon
MOA of warfarin
inhibits vitamin k
Blocks ability of vitamin k to carboxylate vit k dependant clotting factors so reducing their coagulant activity
what reaction is vitamin k involved in
carboxylation
what is vitamin k
fat soluble vitamin absorbed in upper intestine
requires bile slats to for absorption
vitamin k dependant fcators
factors II , VII, IX & X
PROTEIN C AND S
monitoring of warfarin
international normalised ratio - INR
major adverse effect of warfarin
haemorrhage
factors that may influence bleeding risk
Intensity of anticoagulation
Concomitant clinical disorders
Concomitant use of other medications
BEWARE DRUG INTERACTIONS
Quality of management
what is warfarin metabolised by and where
cytochrome p450 in the liver - same which metabolises alcohol
bleeding complications of warfarin
Mild
skin bruising
epistaxis
haematuria
Severe
gastro-intestinal
intracerebral
significant drop in Hb
what to give for warfarin reversal
vit k - inr will come down in 6 hours
or clotting factors - immediate affect
new anticoags use
initially used instead of lmwh as prohylaxis in elective hip and knee replacement surgery
used for dvt and pe
introduced for stroke prevention in afib for new patients
examples of new anticoags
Direct activated factor X inhibitors (eg edoxaban, rivaroxaban, apixaban)
Direct thrombin inhibitors (dabigatran)
benefits of new anticoags
Oral and no monitoring required
Less drug interactions
