Drugs

Question 1

ANTICOAGULANTS

Describe the mechanism of action of warfarin.

Answer 1

Vit K antagonist, prevents synthesis of vit K dependent clotting factors 2, 7, 9, 10 and protein C and S.

Question 2

ANTICOAGULANTS

What are the indications for warfarin ?

Answer 2

DVT, AF, MI, pulmonary embolism, mitral stenosis, prosthetic heart valves.

Question 3

ANTICOAGULANTS

What is the normal INR ?

Answer 3

INR 1

Question 4

ANTICOAGULANTS

What does INR measure ?

Answer 4

Prothrombin time.

Question 5

ANTICOAGULANTS

How often should INR be checked in patients which have stabilised their warfarin INR ?

Answer 5

Every 4-8 weeks.
Will be more regular if poorly controlled.

Question 6

ANTICOAGULANTS

How long before a procedure should a patient taking warfarin’s INR be checked ?

Answer 6

24 hours ideally.
Up to 72 hours if stable.

Question 7

ANTICOAGULANTS

What drugs can cause an increase in INR in patients taking warfarin ?

Answer 7

Antibiotics, NSAIDs.

Question 8

ANTICOAGULANTS

SDCEP GUIDANCE - your patient’s INR is >4 and they require an extraction, how do you manage this patient ?

Answer 8

Post-pone treatment until INR under control.
If emergency treatment required - refer to secondary care.

Question 9

ANTICOAGULANTS

SDCEP GUIDANCE - your patient’s INR is between 2-4 and is taking warfarin, and they require an extraction, how do you manage this patient ?

Answer 9

Can be treated.

Question 10

ANTICOAGULANTS

How does SDCEP guidance suggest extra measures you can use to manage a patient taking warfarin if they have an INR 2-4 ?

Answer 10

Staging of treatment.
Delay treatment if short term use.
Treat early in day and early in week.
Use atraumatic techniques.
Avoid IDB where possible.
Use local haemostatic measures.
Give good post-operative advice.
Ensure bleeding has stopped for 30 mins after procedure.

Question 11

ANTICOAGULANTS

What medications should you not prescribe to a patient on Warfarin ?

Answer 11

Aspirin, NSAIDs, azoles.

Question 12

ANTICOAGULANTS

Describe the mechanism of action of apixiban.

Answer 12

Inhibits factor Xa - preventing the production of thrombin.

Question 13

ANTICOAGULANTS

Describe the mechanism of action of rivaroxaban.

Answer 13

Factor Xa inhibitor - prevents production of thrombin.

Question 14

ANTICOAGULANTS

What is the mechaism of action of dabigatran ?

Answer 14

Inhibits thrombin directly.

Question 15

ANTICOAGULANTS

How often do patients take apixiban tablets ? How should their medication be managed if undergoing high risk treatment ?

Answer 15

2x daily.
Miss morning dose, continue with normal night time dose.

Question 16

ANTICOAGULANTS

How often do patients take dabigatran ? How should their medication be managed if undergoing high risk treatment ?

Answer 16

2x daily.
Miss morning dose, continue with night time dose as normal.

Question 17

ANTICOAGULANTS

How often do patients take rivaroxaban ? How should their medication be managed if undergoing high risk procedures ?

Answer 17

1x morning dose.
Delay morning dose until 4 hours since HA.

Question 18

ANTICOAGULANTS

How often do patients take edoxaban ? How should their medication be managed if they are undergoing high risk treatment ?

Answer 18

1x night time dose.
Take treatment as usual at night.

Question 19

ANTICOAGULANTS

What reasons would you not change a patients NOAC medication regime for treatment ?

Answer 19

Taking for mitral heart valves or coronary stent.
Have had pulmonary embolism or DVT in last 3 months.
Taking for cardioversion.

Question 20

ANTICOAGULANTS

Your patient is taking low weight molecular weight heparin (injectable anticoagulants) - how do you manage their medication if they require high risk treatment ?

Answer 20

Treat without interrupting.

Question 21

ANTIPLATELETS

Name some antiplatelet drugs.

Answer 21

Aspirin, clopidogrel, prasugrel, dipryridamole.

Question 22

ANTIPLATELETS

How should you manage your patients drug regime if they require high risk procedure and are taking a single or dual antiplatelet drug ?

Answer 22

Do not interrupt medication.

Question 23

ANTIPLATELETS

How should you manage a patient’s drug regime if they require a high risk procedure and are taking an anticoagulant and antiplatelet drug ?

Answer 23

Consult prescribing clinician.