Anti-coagulant

Question 1

What are the examples of Direct acting oral anticoagulants (DOACs)?

Answer 1

Dabigatran, Rivaroxaban, Apixaban

These are commonly prescribed anticoagulants for various indications.

Question 2

What is the mechanism of action (MOA) of Dabigatran?

Answer 2

Direct thrombin inhibitor

Question 3

What is the MOA of Rivaroxaban and Apixaban?

Answer 3

Inhibit factor Xa inhibitor

(‘Xa’ ‘ban’ = 10 a inhibitor)

Question 4

What are the indications for prescribing DOACs?

Answer 4

VTE prophylaxis, DVT/PE treatment, AF

Other risk factors should be present for prescription, such as prior stroke, age 75+, hypertension, diabetes, heart failure.

Question 5

What is the MOA of Fondaparinux?

Answer 5

Activates antithrombin III + neutralises factor Xa

Question 6

List the indications for Fondaparinux.

Answer 6

• VTE prophylaxis (major surgery)
• DVT + PE
• Unstable angina + NSTEMI

Question 7

What are the complications associated with Fondaparinux?

Answer 7

Anaemia + haemorrhage

Question 8

What are the two types of heparin mentioned?

Answer 8

• Unfractionated heparin (UH)
• Low molecular weight heparin (LMWH)

Question 9

What is the moa of heraprins?

Answer 9

Question 10

What is the MOA of Warfarin?

Answer 10

Vitamin K antagonist, prevents formation of active vitamin K

Question 11

What clotting factors are affected by Warfarin?

Answer 11

• II
• VII
• IX
• X

1972 - these clotting factors are activates by vitamin K.

Question 12

What are the indications for Warfarin?

Answer 12

VTE, AF, mechanical heart valves

Question 13

List the contraindications for Warfarin.

Answer 13

• Liver disease
• NSAIDs
• Cranberry Juice
• P450 enzyme inhibitors

Question 14

What are the side effects of Warfarin?

Answer 14

• Haemorrhage
• Teratogenic
• Skin necrosis
• Purple toes

Question 15

What are the reversal agents for Warfarin?

Answer 15

Vitamin K, prothrombin complex concentrate (PCC)

Question 16

How are patients on warfarin monitored?

Answer 16

INR

Ratio of prothrombin time to the patient over the normal prothrombin time. Normal INR = 1.0 (approx).

Question 17

What is the normal INR value?

Answer 17

1.0 (approx)

Question 18

What is the target INR for VTE treatment?

Answer 18

2.5 (3.5 if recurrent)

Question 19

What is the target INR for AF?

Answer 19

2.5

Question 20

What is the target INR for mechanical heart valves?

Answer 20

• 3.0 (aortic)
• 3.5 (mitral)

Question 21

Why is bridging necessary when initiating Warfarin?

Answer 21

Warfarin is slow acting

Question 22

What short-acting anticoagulant is used to bridge the gap when initiating Warfarin?

Answer 22

LMWH

Question 23

What safety measure must patients on Warfarin carry?

Answer 23

A yellow oral anti-coagulant book

Question 24

How do you manage bleeds and high INR in Warfarin?

Answer 24