Pharmacology Flashcards
action of heparin
acts on antithrombin increasing its action
preparation of heparin
immediate effect
given parenteral IV or SC
two forms of heparin
unfractionated
LMWH
is heparin safe in pregnancy?
yes
what is used to monitor unfractionated heparin?
APTT
what is used to monitor LWMH?
anti-Xa assay
complications of heparin
bleeding
heparin-induced thrombocytopenia with thrombosis (HITT)
OP with long-term used
what to check if heparin-induced thrombocytopenia with thrombosis is suspected
FBC
how do you reverse heparin bleeding?
protamine sulphate
examples of coumarin anticoagulants
warfarin
pheninone
acenocoumarin
phenprocoumon
action of coumarin anticoagulants
inhibit vitamin K
what is vitamin K?
fat soluble vitamin
how is vitamin K absorbed?
upper SI with bile acids
which are the vitamin K coagulation factors?
II (prothrombin)
VII
IX
X
protein C and S
why is warfarin started with heparin to begin with?
avoid thrombosis due to drop in naturally occurring anticoagulants (protein C and S)
how long is heparin started with warfarin?
5-7 days
how is warfarin monitored?
INR as has narrow therapeutic window (PT)
adverse of warfarin
haemorrhage
mild bleeding
what increases the risk of haemorrhage on warfarin?
intensity concomitant clinical disorders (elderly have fragile vessels, ulcers) other medications (liver CYP450s)
mild bleeding that can occur in warfarin
bruising
epistaxis
haematuria
reversal of warfarin
omit dose(s)
administer vitamin K
if severe give FFP (clotting factors)
two types of new anticoagulants
- oral direct thrombin inhibitors
2. Xa inhibitors
example of oral direct thrombin inhibitors
dabigatran
why are oral direct thrombin inhibitors second line?
can cause renal impaired
examples of Xa inhibitors
edoxaban
rivaroxaban
apixaban
monitoring of new oral anticoagulants
not need
action of aspirin
inhibits COX (cyclo-oxygenase) which is necessary for production of thromboxane A2
adverse of aspirin
it is an NSAID, so:
- bleeding
- blocks prostaglandins
- GI ulceration
- bronchospasm
action of clopidogrel, ticagresler and prasugrel?
ADP receptor antagonists (P2Y12)
action of dipyridamole
PDE inhibitor of cAMP (second messenger in platelet activation)
action of abciximab
GPIIb/IIIa inhibitor preventing platelet aggregation
examples of antiplatelets
aspirin
clopidogrel, prasugel
dipyridamole
abciximab
reversal of anticoagulants
platelet transfusion
