Clinical anticoagulants

Question 1

Why are platelets important for clotting?

Answer 1

They provide the phospholipid surface
Contain clotting factors
binds collagen, vWF and fibrinogen

Question 2

What is the structure of serine proteases?

Answer 2

They have a GIa domain which is hydrophobic to bind to the phospholipid surface

Question 3

what are some serine proteases?

Answer 3

Clotting factors II,VII,FIX,X

Question 4

in brief how is the fibrin strand produced?

Answer 4

Prothrombin is converted to thrombin by FX.

thrombin can then convert fibrinogen to fibrin.

Question 5

what are some indications for anticoagulation?

Answer 5

• AF
• Valvular heart disease
• cardiomyopathy
• VTE
• MI

Question 6

what factors does the CHAD 2 score take into account?

Answer 6

CHF
hypertension
Stroke/TIA
Age>75
Diabetes 
valvular disease
female

Question 7

what factors does HASBLED take into account?

Answer 7

• hypertension
• abdominal, renal or liver dysfunction
• Stroke
• Bleeding
• INR
• eldery
• drugs/ alcohol

Question 8

using the CHAD system who gets anticoagulants?

Answer 8

all men with a score of 1

anyone with a score of 2

Question 9

why can factor 8 increase after surgery?

Answer 9

its an acute phase reactant

Question 10

what are absolute contraindications of anticoagulants?

Answer 10

Acute bleedings

Question 11

what are relative contraindications of anticoagulation?

Answer 11

Active peptic ulceration
alcohol or drug use
poor compliance
severe liver disease
renal impairment
uncontrolled hypertension
dementia
pregnancy

Question 12

what is unfractionated heparin?

Answer 12

a linear sulphated polysaccharide consisting of negatively charged glycosaminoglycans with a 1;1 raio of anti X and anti II

Question 13

what is low molecular weight heparin?

Answer 13

Has differing Anti X and anti II ratio’s

produced by depolymerisation of unfractionated heparin

Question 14

how is heparin produced?f

Answer 14

from bovine lung/ porcine intestine

Question 15

what is the MOA of heparin?

Answer 15

it binds to anti thrombin causing a conformational change, this increases the inhibiton of FX and thrombin

Question 16

how is unfractionated heparin cleared?

Answer 16

reticuloendothelial

Question 17

what is the half life of unfractionated heparin?

Answer 17

1.5 hours

Question 18

how is unfractionated heparin given?

Answer 18

IV or sc

Question 19

what is the reversal for unfractionated heparin?

Answer 19

protamine

Question 20

how is LMWH cleared?

Answer 20

renal

Question 21

what is the half life of LMWH?

Answer 21

12 hours

Question 22

what is the amount of time before LMWH is peak?

Answer 22

3-4hours

Question 23

how is LMWH administered?

Answer 23

Sc

Question 24

what is the reversal for LMWH?

Answer 24

minimal reversal can be achieved with protamin

Question 25

what people need anti Xa monitoring?

Answer 25

Pregnant people renal impairment Obesity

Question 26

what tests will unfractionated heparin effect?

Answer 26

APTT

Question 27

What tests will LMWH effect?

Answer 27

Anti Xa

Question 28

what tests will vitamin K antagonists affect?

Answer 28

PT/INR

Question 29

what tests will dabigatren affect?

Answer 29

TT

Question 30

what are the side effects of heparin?

Answer 30

- bleeding - thrombocytopenia - osteoporosis

Question 31

what do you do for heparin induced thrombocytopenia with thrombosis?

Answer 31

stop heparin and given danaparoid or hirudin

Question 32

how does warfarin work?

Answer 32

Its a vitamin K antagonist

Question 33

What process does vitamin K interfer with?

Answer 33

gamma carboxylation of GIa domain

Question 34

what does gamma carboxylation of the GIa domain normally allow?

Answer 34

interaction with the phospholipid of platelet membranes which localises coagulation

Question 35

how is warfarin initiated in patients with thrombosis?

Answer 35

with heparin

Question 36

what is warfarin dose sensitive to?

Answer 36

diet drugs ethnicity age

Question 37

what test is warfarin monitored with?

Answer 37

INR/PT

Question 38

For warfarin VTE prophylaxis what INR is ideal?

Answer 38

2-2.5

Question 39

For people on warfarin due to mechanical heart valves what INR value is ideal?

Answer 39

3-4

Question 40

for people on warfarin due to antiphospholipid syndrome what INR is a good range?

Answer 40

2.5-3.5

Question 41

what are the side effects of warfarin?

Answer 41

Bleeding, skin necrosis, birth skeletal abnormalities, increased foetal loss

Question 42

what does warfarin cause skin necrosis?

Answer 42

Due to a protein C deficiency

Question 43

what does warfarin cause birth skeletal abnormalities

Answer 43

Lack of gamma carboxylation of bone protein takens place

Question 44

how do DOAC's work?

Answer 44

targeted inhibition of Xa or thrombin

Question 45

what tests can be done to monitor dabigatran?

Answer 45

aPTTR

Question 46

what does a normal TT mean in dabigatran?

Answer 46

It excludes the possibility that there is any circulation

Question 47

what is the reversal agent for dabigatran?

Answer 47

idarucizumab