Brainscape's Knowledge GenomeTM

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


See full index

Hematology > Anticoagulant drugs > Flashcards

Anticoagulant drugs Flashcards

1
Q

Why do heparin and warfarin need constant monitoring?

A

Narrow therapeutic window

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

Name the two types of thrombotic events

A

arterial - atherosclerosis

Venous - stasis, fibrin clot

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

What are the indications for anticoagulant drugs?

A

Venous thrombosis

Atrial fibrillation - blood clot on left atrial wall due to stasis caused by irregular contractions

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

What is the consequence of atrial fibrillation?

A

Stroke

Embolus travels to cerebral circulation

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

What are the naturally occuring anti-coagulants?

A
  1. Serine protease inhibitors - anti thrombin binds to thrombin which prevents fibrinogen conversion to fibrin
  2. Protein C and S - these are not usually targeted by drugs. Note that these are vit K (thus affected by warfarin)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is heparin?

A

potentiates antithrombin

immediate effect

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

What route is heparin given?

A

Iv or SC

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

What are the 2 forms of heparin?

A

Unfractionated (IV form)

Low molecular weight (LMWH)

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

Why is LMWH preferred over unfractionated heparin?

A

Needs a lot more monitoring, LMWH is predictable and given based on patient’s weight

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

What is the MOA of unfractionated heparin?

A

Unfractionated heparin joins antithrombin to thrombin forming a complex – potentiating effect

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

What is the MOA of LMWH?

A

keps antithrombin and factor Xa together in a complex.

This prevents the conversion of prothrombin to thrombin

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

How is heparin monitored?

A

APTT - for unfractionated

Anti Xa assay for LMWH - usually LMWH is not monitored (except in obesity and pregnancy)

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

What are the complications for heparin?

A

Risk of bleeding - small compared to no treatment

HITT - antibodies to platelet fomring a complex. Platelets aggregate and then drop. risk of life threatening thrombosis

Osteoporosis with long term use - interferes with bone metabolism

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

Patient on anticoagulants has a significant drop in platelet. What to check for?

A

Check for antibodies of Heparin induced thrombocytopenia

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

Heparin reversal

A

Stop the heparin

In severe bleeding
Protamine sulphate (unfractionated heparin) reverses antithrombin effect.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the role of protamine sulphate in unfractionated and LMWH?

A

Unfractionated = complete heparin reversal

LMWH = partial reversal

17
Q

List the coumarin anticoagulants

A

warfarin
phenindione
acenocoumarin
phenprocoumon

18
Q

Vitamin K and clotting

A

Fat soluble
Synthesised in liver
Required for the final carboxylation of clotting factors 2, 7, 9 & 10 - essential for function

19
Q

Where is warfarin metabolised?

A

Warfarin is metabolised in the liver

20
Q

Stages of warfarin therapy

A

Initiation - rapid or dlwo
Stabilisation
Maintenance

21
Q

What precaution to be taken when administering warfarin?

A

Narrow therapeutic window, hence close monitoring needed

22
Q

What is INR?

A

Ratio of prothrombin time calibrated for different reagents in different labs in order to standardise globally

23
Q

What is the major AE of warfarin?

A

BLEEDING

24
Q

List the features that influence bleeding risk when on warfarin

A 
Intensity of anticoagulation
Concomitant clinical disorders
Concomitant use of other medications 
BEWARE DRUG INTERACTIONS
Quality of management
25
Q

What is the target INR?

A

2-3

26
Q

What are the mild complications of bleeding when on warfarin?

A

skin bruising
epistaxis
haematuria

27
Q

What are the severe complications of bleeding when on warfarin?

A

gastro-intestinal
intracerebral
significant drop in Hb

28
Q

How to reduce the effect of warfarin?

A

Increase Vit K (IV

29
Q

What to do if there is severe complications of bleeding when on warfarin?

A

Administer clotting factors (factor concentrates)

30
Q

Name the thrombin inhibitor that is renally metabolised and excreted

A

Dabigatran

31
Q

Why is dabigatran CI in elderly

A

Renal metabolism and excretion

UTI

32
Q

List the Xa inhibitors

A

edoxaban
rivaroxaban
apixaban

33
Q

What are the benefits of the new anti-coagulants

A

Direct thrombin inhibitors (dabigatran)
Direct activated factor X inhibitors (eg edoxaban, rivaroxaban, apixaban)
Oral and no monitoring required
Less drug interactions
Recently developed specific antidotes for reversal

34
Q

What is the indication of new anticoagulant drugs

A

Initially used instead of LMWH as prophylaxis in elective hip and knee replacement surgery
Used for treatment of DVT/PE

Stroke prevention in atrial fibrillation for new patients

35
Q

What is the treatment of choice in metal heart valves and anti-phospholipid syndrome?

A

Warfarin

Hematology (9 decks)

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