Anticoagulants

Question 1

which anticoagulants carry a risk of epidural haematoma (collection of blood in between skull and dura mater)

Answer 1

• NOACs and DOACs

e.g (rivaroxaban, dabigatran
apixaban, edoxaban)

note: no evidence of risk with lmwh eg dalteparin

Question 2

name the 2 types of juice that interact with warfarin

Answer 2

Cranberry + pomegranate juice

both increase INR so increase warfarins anticoagulant effect

Question 3

which anticoagulants can be used in pregnancy (e.g for DVT/VTE)

Answer 3

LMWH (low molecular weight heparins):
Dalteparin
Enoxaparin
Tinzaparin

Question 4

how long is rivaroxaban given for to prevent VTE after a KNEE replacement surgery

Answer 4

2 weeks

Question 5

how long is rivaroxaban given for to prevent VTE after a HIP replacement surgery

Answer 5

5 weeks

Question 6

what do you do if: INR 5.0–8.0, no bleeding

Answer 6

withhold 1 or 2 doses of warfarin sodium and reduce subsequent maintenance dose

Question 7

what do you do if: INR 5.0–8.0, minor bleeding

Answer 7

stop warfarin sodium; give phytomenadione (vitamin K1) by slow intravenous injection; restart warfarin sodium when INR <5.0

Question 8

what do you do if: INR >8.0, no bleeding

Answer 8

stop warfarin sodium; give phytomenadione (vitamin K1) by mouth using the intravenous preparation orally [unlicensed use]; repeat dose of phytomenadione if INR still too high after 24 hours; restart warfarin when INR <5.0

Question 9

what do you do if: INR >8.0, minor bleeding

Answer 9

stop warfarin sodium; give phytomenadione (vitamin K1) by slow intravenous injection; repeat dose of phytomenadione if INR still too high after 24 hours; restart warfarin sodium when INR <5.0

Question 10

what do you do if: a patient taking warfarin has a major bleed

Answer 10

stop warfarin sodium; give phytomenadione (vitamin K1) by slow intravenous injection; give dried prothrombin complex (factors II, VII, IX, and X); if dried prothrombin complex unavailable, fresh frozen plasma can be given but is less effective

note: recombinant factor VIIa is not recommended for emergency anticoagulation reversal

Question 11

what should a patients INR ideally be if they are switch from warfarin to a DOAC straight away

Answer 11

<2

Question 12

which PPIs decrease the efficacy of clopidogrel

Answer 12

omeprazole + esomeprazole

Question 13

why should patients on warfarin report if they get a painful skin rash

Answer 13

warfarin use may lead to calciphylaxis ( calcium accumulates in small blood vessels of the fat and skin tissues)

Question 14

what colour is the warfarin 1mg tablet

Answer 14

brown

Question 15

what colour is the warfarin 3mg tablet

Answer 15

blue

Question 16

what colour is the warfarin 5mg tablet

Answer 16

pink

Question 17

how long should a patient take warfarin for isolated calf-vein deep-vein thrombosis

Answer 17

6 weeks

Question 18

how long should a patient take warfarin for VTE provoked by surgery or other transient factors

Answer 18

3 months

Question 19

how long should a patient take warfarin for unprovoked proximal DVT or PE

Answer 19

at least 3 months

Question 20

how long should a patient take warfarin for AF (atrial fibrillation)

Answer 20

lifelong

Question 21

how long should a patient take warfarin for prosthetic heart valve

Answer 21

lifelong

Question 22

what are the contraindications for NOACs (apixaban, dabigatran + rivaroxaban)

Answer 22

• a lesion or condition that is a risk of major bleeding

- concomitant treatment with any other anticoagulant agent

Question 23

which anticoagulant should not be used for thromboprophylaxis in patients with prosthetic heart valves, including patients who have undergone TAVR (transcatheter aortic valve replacement)

Answer 23

rivaroxaban (MHRA warning)

Question 24

which anticoagulants are not recommended in patients with antiphospholipid syndrome

Answer 24

DOACS

note: particularly high-risk patients who test positive for all three antiphospholipid tests—lupus anticoagulant, anticardiolipin antibodies, and anti-beta2 glycoprotein I antibodies. consider switching to warfarin

Question 25

describe how rivaroxaban 15mg + 20mg tablets should be taken (counselling points)

Answer 25

• take with food
• on those who have difficulty swallowing, these tablets can be crushed and mixed with water or apple puree immediately before, and followed by food immediately after, ingestion

Question 26

which anticoagulants are contraindicated in patients with a heart valve

Answer 26

DOACs