l5 Flashcards
what is warfarin-(3)
Anti-coagulant
Vitamin k antagonist
stops platelet formation
Warfarin prevents the carboxylation of factors?
ii, vii, ix, x
what pathway does it prolong
extrinsic pathway
what type of proteins can warfarin inhibit
anti-coagulant proteins
It’s montored via the internationalise d normalised ratio but what ranges should it be between
2.5-3.5-DVT treatment
2-3.5 =recurrent DVT
wht cytochrome helps warfarin interact with other drugs
P450
what can potentiate warfarin
enzyme inhibitors
drugs that inhibit enzymes
allopurinol
ciprofloxacin
erythromycin
drugs that depress action of coumarins
Rifampion
drugs that increase the effects of coumarins
Reduce coumarin binding to serum albumin
Inhibit hepatic microsomal degradation of coumarin
Alteration of receptor site of drug thyroxin
what can decrease vitamin k produce or absorption?
Salicylates
Liver disease
Malabsorption
Side effects of warfarin (5)
Minor bleeding
skin necrosis
Alopecia
Teratogenic-so use LMW heparin in pregnancy
Significant haemorrhage risk-intracranial bleeds
Reversing effects of warfarin (3)
Give vitamin K 2-10mg IV
Give activated prothrombin containing factors, ii, vii ix and x and frozen plasma
What is Heparin
A Mucopolysaccharride that potentiates anti-thrombin.
What factors does it irreversibly activate
iia and xa
how different is low molecular weight heparin given?
It’s given as an injection but regular heparin is given by iv infusion
benefits of heparin compared to warfarin
it’s safe in pregnancy
what is the molecular pathway of heparin
It activates antithrombin, which inactivates conversion of:
xi-xia
ix-ixa
x-xa
what does factor xa contribute to the production of
Prothrombin to thrombin
What does thrombin contribute to the conversion of
fibrinogen to fibrin
Benefit of using unfractionated heparin
safe in renal failure
how can the effects of unfractionated heparin be reversed
giving potassium sulphate
give a name of a heparin
enoxaparin
what does unfractionated heparin treat
thromboprophylaxis
what are the 2 classes of noval oral anticoags
dabigatran
Rivaraxaban
what is a drawback to using dabigatran and rivaraxaban
irreversible anti-coag action
What factors does dabigatran and rivaraxaban inhibit
dabigatran-iia
other-xa
why is dabigatran used
its used to treat VTE (Venous thromboembolism both PE and DVT combined) Prophylaxis
stroke prevention in atrial fibriiation
what is an alternate to dabigatran
argatraban
what is an alternate to rivaroxaban
apixaban
Give 4 types of antiplatelet drugs and their function
Aspirin:cyclo-oxygenase inhibitor
clapidogrel-ADP receptor blocker
Dipyridamole- inhibits phosphodiesterase
Prostacylin- stimulates adenylate cyclase
what are fibrinolytic agents
used to lyse fresh arterial thrombi via converting plasminogen to plasmin
example of a fibrinolytic agent
TPA-tissue plasminogen actvator
streptokinase
when and how are fibrinolytic agents administered?
systematically- in acute MI PE VTE DVT…
