haemostasis

Question 1

haemostatic mechanisms

Answer 1

platelet plug
vasoconstriction
coagulation

Question 2

thrombin converts..

Answer 2

fibringogen into fibrin

Question 3

Why does bernard-soulier syndrome cause bleeding?

Answer 3

platelets do not adhere

Question 4

clotting factor activation dependent on

Answer 4

carboxylation of glutamate

Question 5

factor 5 Leiden mutation causes what genetic disorder?

Answer 5

hypercoagulability disorder

Question 6

vitamin K reduction required for activation of which enzyme?

Answer 6

gamma glutamyl carboxylase

Question 7

reduced vitamin K acts as a …?

Answer 7

co factor

Question 8

why are newborns injected with vitamin K

Answer 8

cannot synthesize K2

Question 9

why can bile acids not be taken with anti-coagulants?

Answer 9

bile acids needed for vitamin K absorption
hemorrhage

Question 10

warfarin background:

Answer 10

oral
derived from coumarin
delayed onset
long half life
narrow therapeutic range

Question 11

how does warfarin lower hydroquonione ?

Answer 11

inhibits VKORC1 which converts expoxide into quinione and then to hydroquinione

Question 12

warfain uses:

Answer 12

DVT and pulmonary emvolism

Question 13

how does warfarin reduce the availability of hydroquinione

Answer 13

similar structure to vitamin K competitive inhibition of VKORC1

Question 14

at which level does warfarin cause inhibiton?

Answer 14

inhibits vitamin K epoxide reductase

Question 15

heparin enhances the activity of which molecule….

Answer 15

antithrombin

Question 16

by enhancing the effect of antithrombin, which molecules are inhibited by heparin?

Answer 16

clotting factor 10a
thrombin

Question 17

limitation of heparin:

Answer 17

no effect on thrombus-bound thrombin

Question 18

half life of heparin vs warfarin

Answer 18

heparin shorter half life

Question 19

heparin can cause a decrease in circulating….

Answer 19

platelet numbers

Question 20

types of direct thrombin inhibitors:

Answer 20

bivalent and univalent

Question 21

DTIS inhibit…

Answer 21

coagulation and platelet activation

Question 22

warfarin and heparin differ to direct thrombin inhibitors in what way?

Answer 22

direct thrombin inhibitors do not have an active site

Question 23

downside of rivaroxban:

Answer 23

expensive

Question 24

effect of antiplatelet drugs:

Answer 24

decrease platelet activation and thrombus formation

Question 25

difference between arterial and venous thrombi:

Answer 25

platelets in a fibrin mesh are found in arterial circulation

Question 26

which drugs have anti-platlelet properties?

Answer 26

NSAIDS and SSRIs

Question 27

3 classes of antiplatlet drugs:

Answer 27

COX1 inhibitors
ADP receptor antagonists
glycoprotein IIb-IIIa antagonists

Question 28

thromboxane 2 role…

Answer 28

enhances platelet activation

Question 29

arachidonic acid is the precusor of what molecule….

Answer 29

prostaglandins via COX enzymes

Question 30

thromboxane is derived from what molecule?

Answer 30

prostaglandin

Question 31

aspirin inhibits the production of what thromboxane precursor?

Answer 31

prostaglandins

Question 32

thromboylsis definition

Answer 32

drug induced clot breakdown

Question 33

what processes do thrombolytic agents enhance?

Answer 33

fibrinolysis via stimulating plasmin production

Question 34

what is the only drug which breaks down clots?

Answer 34

thrombolytic agents

Question 35

function of antifibrinlytic agents

Answer 35

reduce the conversion of plasminogen to plasmin

Question 36

how do bivalent and univalent direct thrombin inhibitors differ?

Answer 36

bivalent bind to two active sites