Brainscape's Knowledge GenomeTM

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


See full index

CARDIOLOGY > ANTICOAGULANTS AND ANTIPLATELETS > Flashcards

ANTICOAGULANTS AND ANTIPLATELETS Flashcards

1
Q

How should you manage warfarin when there is a major bleed?

A

Stop warfarin
Give IV vitamin K and prothrombin complex

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

How should you manage warfarin when INR >8.0?

A

Stop warfarin
Give oral vitamin K (give IV if there is evidence of bleeding) and repeat dose if INR still high after 24 hours
Restart warfarin when INR <5.0

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

How should you manage warfarin when INR 5.0-8.0?

A

If bleeding:
Stop warfarin
Give IV vitamin K
Restart warfarin when INR <5

If no bleeding:
Stop 1-2 doses of warfarin and reduce subsequent maintenance dose

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

Whats the moa of warfarin?

A

Inhibits epoxide reductase which prevents reduction of vitamin K to its active hydroquinone form which then acts as a cofactor in the carboxylation of clotting factor II, VII, IX, X and protein C.
I.e. it inhibits vitamin K dependant clotting factors

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

When is warfarin indicated?

A

Mechanical heart valves
Second line after DOACs for VTE and AF

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

Whats the target INR when on warfarin for mechanical heart valves?

A

Depends on valve type and location - mitral valves require a higher INR than aortic

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

Whats the target INR when on warfarin for VTE?

A

2.5

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

Whats the target INR when on warfarin for AF?

A

2.5

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

How is warfarin monitored?

A

Using international normalised ratio (INR) and using prothrombin time

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

What factors may potentiate warfarin?

A

Live disease
P450 enzyme inhibitors e.g. amiodarone and ciprofloxacin
Cranberry juice
Drugs which displace warfarin from plasma albumin e.g. NSAIDs
Drugs that inhibit platelet function e.g. NSAIDs

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

What are side efefcts of warfarin?

A

Haemorrhage
Teratogenic (not breast feeding)
Skin necrosis
Purple toes

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

Why is warfarin usually started concurrently with heparin at first?

A

As when you first start warfarin, biosynthesis of protein C is reduced = temporary procoagulant state

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

Whats the MOA of unfractionated heparin?

A

Forms a complex with antithrombin III and inhibits thrombin, factors IXa, Xa, XIa and XIIa

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

Whats the moa of LMWH?

A

Activates antithrombin III and forms a complex that inhibits factor Xa

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

What are examples of DOACs?

A

Dabigatran
Rivaroxaban
apixaban
Edoxaban

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

Whats the moa of dabigatran?

A

Direct thrombin inhibitor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Whats the moa of rivaroxaban, apixaban, edoxaban?

A

Direct factor Xa inhibitor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is fondaparinux?

A

A synthetic pentasaccharide that inhibs activated factor Xa
(shaped like heparin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How is unfractionated heparin administrated?

A

IV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How is LMWH administrated?

A

Subcutaneously

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are examples of LMWH?

A

Dalteparin
Enoxaparin
Nadroparin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How is fondaparinux administered?

A

Subcutaneous injection

23
Q

What are contraindications for all heparins?

A

Acute bacterial endocarditis
After major trauma
Epidural anaesthesia with treatment disease
Haemophilia/other haemorrhagic disorders
Peptic ulcers
Recent cerebral haemorrhage
Recent eye Surrey, NS surgery
Spinal anaesthesia with treatment diseases
Thrombocytopenia

24
Q

What are the SE for all heparins?

A

Haemorrhage
Heparin-induced skin reaction
Hyperkalaemia
Osteoporosis
Alopecia
Spinal haematoma

25
Q

What monitoring is done for all heparins?

A

Platelet count - before starting treatment, and ongoing - to check for heparin-induced thrombocytopenia (if taking for >4 days)
Plasma K+ concentration before starting and regularly there after - hyperkalaemia (if taking for >7 days)

26
Q

Why is LMWH used more routinely than unfractionated heparin?

A

LMWH doesnt require anticoagulant monitoring
Decreased risk of heparin-induced thrombocytopenia and osteoporosis
Duration of action is longer so once-daily subcutaneous administration may be possible

27
Q

How does the duration of action of heparins differ?

A

LMWH has longer duration of action than unfractionated heparin

28
Q

What monitoring should be done for heparin?

A

LMWH - no routine monitoring required
Unfractionated - monitor activated partial thromboplastin time

29
Q

When is unfractionated heparin more useful than LMWH?

A

Useful in situations where there is a high risk of bleeding as anticoagulation can be terminated rapidly. Also useful in renal failure

30
Q

How do you reverse a heparin overdose?

A

Protamine sulphate (note it only partially reverses the effects of LMWH)

31
Q

What are options for parenteral anticoagulation?

A

Unfractionated heparin
LMWH
Fondaparinux
Direct thrombin inhibitors

32
Q

Whats an example of a direct thrombin inhibitor taken parenterally?

A

Bivalirudin

33
Q

What are the options for oral anticoagulation?

A

DOACs
Warfarin

34
Q

What are the examples of DOACs licensed for use in the UK?

A

Dabigatran
Rivaroxaban
Apixaban
Edoxaban

35
Q

Why is warfarin still needed as a drug?

A

It’s used for patients with metallic heart valves

36
Q

What metabolises warfarin?

A

CYP450-2C9

37
Q

What can reduce P450s anticoagulation effect?

A

CYP2C9 inducers - rifampicin, carbamazepine, phenytoin, pyrimidone
Some calcium supplements
ST/johns wort

38
Q

What can increase the action of warfarin and therefore increase bleeding risk?

A

Altered intestinal flora with reduced intestinal vitamin K synthesis - antibiotics
Inhibitors of hepatic CYP2C9 - fluconazole, amiodarone, metronidazole, sulfamethoxazole, gemfibrozil
Anything that binds albumin and therefore displaces warfarin
Anything that injures GI mucosa e.g. aspirin and NSAIDs
Anything that interferes with platelet function e.g. anti-platelets
Chamomile tea
Fenugreek
Ginkgo biloba

39
Q

What is INR?

A

International normalised ratio
It’s the prothrombin time that is agreed globally

40
Q

Who should have a target INR of 3.5?

A

Pt with recurrent DVT or PE if already recieving anticoagulation and have an INR >2

41
Q

When should warfarin be stopped regarding surgery?

A

5 days before but given the day before surgery if INR is >1.5

42
Q

Contraindications for warfarin

A

Avoid use within 48 hours postpartum
Haemorrhagic stroke
Significant bleeding
Pregnancy
Allergies

?
Severe liver/kidney disease
Endocarditis in past
History of GI bleeding
Hypertension

43
Q

How do we monitor warfarin?

A

Base-line prothrombin time
Daily INR in early days ands then at longer intervals up to every 12 weeks

44
Q

What should you ensure everyone on warfarin has?

A

An anticoagulant treatment booklet (yellow book)

45
Q

What is in an anticoagulant treatment booklet?

A

Records recent INR
Dosage information
Advice on anticoagulation
Alert card which should be carried by the pt at all times

46
Q

Why is it suggested to take warfarin in the evening?

A

This is so that if you need to change the dose after a routine blood test, you can do this the same day rather than waiting until the following morning.

47
Q

What foods can affect warfarin?

A

Foods containing lots of vitamin K e.g. green leafy veg, chickpeas, liver, egg yolks, mature /blue cheese, avocado, olive oil

Cranberry and grapefruit juice can increase effect of medication and put you at high bleeding risk

48
Q

What are indications for DOACs?

A

Apixaban, dabigatran, edoxaban + rivaroxaban - prevention stroke, systemic embolism with non-valvular AF in specific circumstances, treating and secondary prevention or DVT/PE
Apixaban, dabigatran and rivaroxaban - prevention of VTE after elective hip/knee replacement surgery
Rivaroxaban - prevention atherothrombotic events in pt with CAD or PAD and following ACS

49
Q

What monitoring is done for DOACs?

A

No routing anticoagulant monitoring is required

50
Q

When does the anticoagulant effect of DOACs diminish after the last dose?

A

12-24 hours (omitted/delayed doses could lead to a reduction in anticoagulant effect BUT also means unlikely to need reversal agents)

51
Q

What are reversal agents for warfarin?

A

Vitamin K1
Prothrombin complex concentrate

(Second line - fresh frozen plasma)

52
Q

Whats the reversal agent for dabigatran?

A

Idarucizumab

53
Q

Whats the reversal agent for apixaban or rivaroxaban?

A

Andexanet Alfa

CARDIOLOGY (19 decks)

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