Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Atrial Fibrillation > Pharmacology of Haemostasis and Coagulation > Flashcards

Pharmacology of Haemostasis and Coagulation Flashcards

1
Q

Types of anticoagulants

A

Oral
Hearings
Direct oral anticoagulants (DOACs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is warfarin?

A

Oral anticoagulants

Vitamin k antagonist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What does warfarin do?

A

Blocks vitamin k reductase which is needed for vitamin k to act as a cofactor
Inhibits post-translational modification, therefore no carboxylation of glutamic acid residues
Production of proper coagulation factor is inhibited

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is warfarin used for?

A

Prevent thrombosis:

Patients with replaced heart valves, atrial fibrillation, PE, DVT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How long does it take for warfarin to take effect?

A

Several days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is warfarin monitored by?

A

International normalised ratio with a specific target value and adjust dose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Problems with warfarin

A

Many drug interactions - may be potentiated by a range of drugs
- may be reduced by enzyme inducers
Increased risk to bleeding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Give an example of injectable anticoagulants

A

Unfractionated heparin or Low Molecular Weight Heparin

Eg. Enoxaparin, tinzaparin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What do injectable anticoagulants do?

A

Activate antithrombin III (natural protein)

Antithrombin inactivates some clotting factors and thrombin by complexing with serine protease of the factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Difference between injectable anticoagulants and warfarin

A

IAs are immediate and subcutaneous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Use of heparin

A

Prevent thrombosis (particularly DVT), used to prevent clots
Used while warfarin takes effect
Unfractionated heparin monitored with APTT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Example of DOAC

A

Dabigatran - oral thrombin inhibitor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What do DOACs do?

A

prevents thromboembolism by inhibiting the coagulation factors in the cascade

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why are DOACs better than warfarin?

A

less bleeding
fewer drug interactions
does not require monitoring
equally as effective

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Why are DOACs not better than warfarin?

A

effects are less easily reversed

expensive antidote

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are prostacyclin/nitric oxide?

A

endothelial derived vasodilators

17
Q

What does prostacyclin do?

A

PGI2 - prevents platelet aggregation

acts on platelets to increase cAMP

18
Q

What does thromboxane do?

A

promotes aggregation, decreases cAMP

19
Q

What does nitric oxide do?

A

prevents both platelet adhesion and aggregation by increasing platelet cGMP

20
Q

Give examples of antiplatelet drugs?

A

low dose aspirin (75mg)

dipyridamole

21
Q

What is low dose aspirin used for?

A

prevent MI in ps who have previously had a MI
(not for primary prevention)
reduces incidence of stroke

22
Q

How does low dose aspirin work?

A

inhibits cyclo-oxygenase irreversibly so free arachidonic acid cannot be made into endoperoxides which in turn form PGI2 and thromboxane
thromboxane is a platelet and therefore has no nucleus whereas PGI2 is an endothelial cell and therefore the nucleus regenerates COX

23
Q

What is dipyridamole?

A

antiplatelet drug

24
Q

What is dipyridamole used for?

A

prevention of thrombosis

used in conjunction with aspirin, enhances effect of aspirin

25
Q

How does dipyridamole work?

A

phosphodiesterase inhibitor - prevents breakdown of cAMP and cGMP (which are broken down by phophodiesterase)
therefore inhibits aggregation
also inhibits adenosine uptake

26
Q

What is GP IIb/IIIa?

A

expressed from ADP from aggregating platelets

binds fibrinogen which leads to cross-linking of platelets

27
Q

What does clopidogrel do?

A

inhibits ADP induced expression of GP, ie prevents ADP activating platelets

28
Q

When is clopidogrel used?

A

for ps who can’t take aspirin

used with aspirin after a heart attack

29
Q

Why is aspirin not used for primary prevention?

A

risk of gastric bleeding

30
Q

What is abciximab?

A

monoclonal antibody against GP IIb/IIIa

31
Q

When is abiciximab used?

A

ps undergoing angioplasty (catheter and balloon to open up coronary artery)

32
Q

Give an example of fibrinolytic drug/protein

A

alteplase

33
Q

What is fibrinolysis?

A

break down of fibrin
endogenous system to dissolve clots, activated with clotting system
plasminogen becomes activated to form plasmin

34
Q

What is plasmin

A

part of fibrinolysis
enzyme which digests fibrin of the clot and also some of the clotting factors
dissolves it

35
Q

What do fibrinolytic agents do?

A

activate plasminogen to plasmin conversion

36
Q

What are thrombolytics used for?

A

given after MI to dissolve thrombus that has caused blockage of coronary arteries and the MI
pulmonary embolism
thromboembolic stroke

37
Q

What are thrombolytics used with?

A

with aspirin, but need care can cause bleeding

38
Q

What is alteplase used for?

A

ischaemic strokes
dissolves clot and restores blood flow, saving neurons
must be given <4 hours post-stroke

Atrial Fibrillation (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions