Anti-coagulants

Question 1

What does Vitamin K do

Answer 1

It is an essential vitamin for the functioning of clotting factors in the blood

Question 2

What does warfarin do

Answer 2

Antagonises vitamin K

Question 3

What is the prothrombin time

Answer 3

Time it takes for blood to clot

Question 4

What does warfarin do to the prothrombin time

Answer 4

Increases the time

Question 5

What does the INR measure

Answer 5

How anticoagulated a patient is

Question 6

What enzyme is warfarin affected by

Answer 6

cytochrome P450

Question 7

Who is warfarin the anticoagulant of choice for

Answer 7

Patients with mechanical heart valves, valvular AF and end stage renal failure

Question 8

Which clotting factors does vitamin K synthesise

Answer 8

II, IV, IX, X and proteins C and S

Question 9

What do DOACs inhibit

Answer 9

Single blood clotting factor

Question 10

What does Dabigatran inhibit

Answer 10

Thrombin

Question 11

What does Rivaroxaban inhibit

Answer 11

Activated factor Xa

Question 12

What does Apixaban inhibit

Answer 12

Activated factor Xa

Question 13

What does Edoxaban inhibit

Answer 13

Activated factor Xa

Question 14

Indications for warfarin

Answer 14

Treatment of VTE, AF, rheumatic heart disease, mechanical heart valves, mitral valve disease

Question 15

Contraindications for warfarin

Answer 15

malignancy, hypersensitivity to warfarin, haemorrhagic stroke, clinically significant bleeding, potential bleeding lesions, uncorrected major bleeding diathesis, pregnancy, uncontrolled severe HTN, drugs which increase risk of bleeding, some patient factors (falls)

Question 16

How long before major surgery must warfarin be stopped

Answer 16

72 hours

Question 17

Which anticoagulant is used in patients with malignancy

Answer 17

Heparin or DOAC

Question 18

Most common side effect of warfarin

Answer 18

Easy bruising, epistaxis, bleeding for longer with simple wounds

Question 19

Life threatening bleeding to watch out for when on anti coags

Answer 19

Prolonged epistaxis, haematemesis, haematochezua, melaena, haemoptysis, haematuria, menorrhagia

Question 20

Side effects of warfarin

Answer 20

Hypersensitivity, rash, alopecia and haemorrhage

Question 21

What is the benefit of warfarin over DOACs

Answer 21

Warfarin can be easily reversed

Question 22

Ways to reverse the effects of warfarin

Answer 22

Withholding warfarin.
Vitamin K oral or IV.
Prothrombin complex concentrate.

Question 23

Drugs which decrease the amount of active warfarin

Answer 23

alcohol, allopurinol, paracetemol, SSRIs, lipid-regulating drugs, influenza vaccine

Question 24

Drugs which increase the amount of active warfarin

Answer 24

oral contraceptives and st johns wort

Question 25

Diet interactions with warfarin

Answer 25

Foods high in vitamin K such leafy green veg, and cranberries

Question 26

Advantages of DOACs over warfarin

Answer 26

No monitoring, no major interactions, slightly less risk of bleeding, slightly better at preventing strokes in AF

Question 27

Examples of DOACs

Answer 27

Apixaban, rivaroxaban, dabigatran

Question 28

What does the CHA2DS2-VASc score assess

Answer 28

Whether a patient with AF should be started on anticoagulation

Question 29

What does the CHA2DS2-VASc score stand for

Answer 29

Congestive HF Hypertension Age >75 scores 2 Diabetes Stroke or TIA prev scores 2 Vascular disease Age 65-74 Sex female

Question 30

the CHA2DS2-VASc score to offer anticoagulation

Answer 30

>1

Question 31

What is the orbit tool

Answer 31

Assessing a patients risk of major bleeding whilst on anticoagulation

Question 32

What does the orbit score use to calculate risk

Answer 32

Low haemoglobin Age above 75 Prev bleeding Renal function Antiplatelet medications

Question 33

What is the HAS-BLED score

Answer 33

Assesses the risk of major bleeding whilst on anticoagulation

Question 34

What does HASBLED stand for

Answer 34

Hypertension, Abnormal renal and liver function, Stroke, Bleeding, Labile INRs, Elderly, Drugs or alcohol

Question 35

Which anticoagulant needs monitoring

Answer 35

Unfractioned heparin and warfarin

Question 36

INR for prophylaxis of DVT

Answer 36

2-2.5

Question 37

INR for treatment of DVT

Answer 37

2.5-3.5

Question 38

INR for recurrent DVT

Answer 38

3.5

Question 39

Risk of unfractioned heparin

Answer 39

Haemorrhage, HIT, osteroporosis

Question 40

Risk of LMWH

Answer 40

Less risk of HIT and osteoporosis, not reversed by protamine

Question 41

Things which increase activity of warfarin

Answer 41

Alcohol, cimetidine

Question 42

Things which decrease activity of warfarin

Answer 42

Phenytoin, phenobarbitone

Question 43

Eg of oligosacharide

Answer 43

Fondoparinux

Question 44

Eg of thrombin inhibitor

Answer 44

Lepirudin and dabigatran

Question 45

Eg of factor X inhibitor

Answer 45

Rivaroxiban