Anticoagulants Flashcards
what is the mechanism of warfarin
vitamin K antagonist
which clotting factors does warfarin prevent the activation of
II, VII, IX and X
does warfarin affect the intrinsic or extrinsic pathway
extrinsic
should warfarin be stopped before surgery
yes- it has a slow half life so needs to be stopped 3 days before surgery
give an example of a drug which will displace warfarin from being bound to albumin
NSAIDs
give some examples of drugs which will inhibit the hepatic metabolism of warfarin
amiodarone, quinolone, metronidazole
what drugs can reduce vitamin K in the gut to enhance warfarin
cephalosporin antibiotics
which drugs can inhibit warfarin
anti epileptics, rifampicin, St Johns Wort
how is warfarin monitored
by looking at the PT and INR
what are the side effects of warfarin
teratogenic, bruising, bleeding, risk of haemorrhage
when is warfarin used
in patient with AF, prosthetic heart valves or previous DVT/PE
how do you reverse the affects of warfarin in an overdose
give vitamin K but this is slow acting so give fresh frozen plasma for fast results
what is the mechanism of action of heparins
activate anti-thrombin III. this can then deactivate clotting factors
what clotting factors does LMWH deactivate
Xa only
what clotting factors does Fractionated heparin deactivate
Xa and thrombin
does heparin use need monitoring
only for fractionated not LMWH
how do you monitor heparin
APTT
what are the uses of LMWH
- prevention of thrombosis-embolism in immobile patients or before surgery
- as a loading dose for DVT/PE patients before warfarin
- acute coronary syndrome
what are the adverse effects of heparin
bruising
bleeding
osteoporosis
thrombocyotopenia
how do you reverse the effects of heparin in an overdose
give protamine sulphate
name 3 anti-platelet drugs
aspirin, dipyridamole, clopidogrel
