Patient on anti-platelet therapy

Question 1

What are examples of ADP receptor inhibitors?

Answer 1

Examples include: Clopidogrel, Prasugrel, Ticagrelor, Ticlopidine.

Question 2

What is the mechanism of ADP receptor inhibitors?

Answer 2

ADP is one of the main platelet activation factors, mediated by G-coupled receptors P2Y1 and P2Y12. The main target of ADP receptor inhibition is the P2Y12 receptor, which leads to sustained platelet aggregation and stabilization of the platelet plaque.

Question 3

What is the evidence supporting the use of ADP receptor inhibitors?

Answer 3

Aspirin and ADP inhibitors block different platelet aggregation pathways, showing potential synergy in clinical trials for high-risk patients with acute coronary syndrome (ACS) or undergoing percutaneous coronary intervention (PCI).

Question 4

What do current NICE guidelines recommend for dual antiplatelet treatment in ACS?

Answer 4

NICE guidelines recommend starting dual antiplatelet treatment with Aspirin (75mg daily) and Ticagrelor (90mg twice daily) for 12 months.

Question 5

What are notable adverse effects of ticagrelor?

Answer 5

Ticagrelor may cause dyspnoea due to impaired clearance of adenosine.

Question 6

What are the interactions and contraindications for clopidogrel?

Answer 6

Clopidogrel interacts with proton pump inhibitors like omeprazole and esomeprazole, reducing antiplatelet effects. Absolute contraindications include prior stroke, high risk of bleeding, and prasugrel hypersensitivity.

Question 7

What are the contraindications for ticagrelor?

Answer 7

Ticagrelor is contraindicated in patients with high risk of bleeding, history of intracranial hemorrhage, and severe hepatic dysfunction. Caution is advised in those with acute asthma or COPD due to higher rates of dyspnoea.

Question 8

What is the first line treatment for acute coronary syndrome (medically treated)?

Answer 8

Aspirin (lifelong) & ticagrelor (12 months)

Question 9

What is the second line treatment for acute coronary syndrome (medically treated) if aspirin is contraindicated?

Answer 9

Clopidogrel (lifelong)

Question 10

What is the first line treatment for percutaneous coronary intervention?

Answer 10

Aspirin (lifelong) & prasugrel or ticagrelor (12 months)

Question 11

What is the second line treatment for percutaneous coronary intervention if aspirin is contraindicated?

Answer 11

Clopidogrel (lifelong)

Question 12

What is the first line treatment for TIA?

Answer 12

Clopidogrel (lifelong)

Question 13

What is the second line treatment for TIA?

Answer 13

Aspirin (lifelong) & dipyridamole (lifelong)

Question 14

What is the first line treatment for ischaemic stroke?

Answer 14

Clopidogrel (lifelong)

Question 15

What is the second line treatment for ischaemic stroke?

Answer 15

Aspirin (lifelong) & dipyridamole (lifelong)

Question 16

What is the first line treatment for peripheral arterial disease?

Answer 16

Clopidogrel (lifelong)

Question 17

What is the second line treatment for peripheral arterial disease?

Answer 17

Aspirin (lifelong)

Question 18

How does aspirin work?

Answer 18

Aspirin works by blocking the action of both cyclooxygenase-1 and 2, which are responsible for the synthesis of prostaglandin, prostacyclin, and thromboxane.

Question 19

What is the effect of aspirin on platelets?

Answer 19

The blocking of thromboxane A2 formation in platelets reduces their ability to aggregate.

Question 20

What was the previous guideline for aspirin use in cardiovascular disease?

Answer 20

Until recent guidelines changed, all patients with established cardiovascular disease took aspirin if there was no contraindication.

Question 21

What did the 2010 technology appraisal of clopidogrel change?

Answer 21

Following the appraisal, clopidogrel is now recommended first-line for certain conditions, and the previous guideline of aspirin for all patients is no longer the case.

Question 22

What do recent trials suggest about aspirin in primary prevention?

Answer 22

Two recent trials have cast doubt on the use of aspirin in primary prevention of cardiovascular disease.

Question 23

What did the MHRA update in January 2010 state?

Answer 23

The MHRA issued a drug safety update reminding prescribers that aspirin is not licensed for primary prevention.

Question 24

What do current guidelines recommend for patients with ischaemic heart disease?

Answer 24

Current guidelines recommend aspirin as first-line treatment for patients with ischaemic heart disease.

Question 25

What medications does aspirin potentiate?

Answer 25

Aspirin potentiates oral hypoglycaemics, warfarin, and steroids.

Question 26

Why should aspirin not be used in children under 16?

Answer 26

Aspirin should not be used in children under 16 due to the risk of Reye's syndrome.

Question 27

What is the exception for aspirin use in children?

Answer 27

The exception is Kawasaki disease, where the benefits are thought to outweigh the risks.

Question 28

What do recent RCP guidelines support for TIAs?

Answer 28

Recent RCP guidelines support the use of clopidogrel in TIAs.

Question 29

What do older NICE guidelines recommend for TIAs?

Answer 29

Older NICE guidelines still recommend aspirin + dipyridamole for TIAs, which the RCP states is 'illogical'.

Question 30

What is Clopidogrel?

Answer 30

Clopidogrel is an antiplatelet agent used in the management of cardiovascular disease.

Question 31

When was Clopidogrel previously used?

Answer 31

Clopidogrel was previously used when aspirin was not tolerated or contraindicated.

Question 32

For what conditions is Clopidogrel now used in addition to aspirin?

Answer 32

Clopidogrel is used in addition to aspirin for conditions such as acute coronary syndrome.

Question 33

What is the first-line treatment for patients following an ischaemic stroke?

Answer 33

Following the 2010 NICE technology appraisal, Clopidogrel is now first-line in patients following an ischaemic stroke.

Question 34

What class of drugs does Clopidogrel belong to?

Answer 34

Clopidogrel belongs to a class of drugs known as thienopyridines.

Question 35

What is the mechanism of action of Clopidogrel?

Answer 35

Clopidogrel acts as an antagonist of the P2Y12 adenosine diphosphate (ADP) receptor, inhibiting the activation of platelets.

Question 36

What are some examples of other thienopyridines?

Answer 36

Other examples include prasugrel, ticagrelor, and ticlopidine.

Question 37

What interaction may affect the effectiveness of Clopidogrel?

Answer 37

Concurrent use of proton pump inhibitors (PPIs) may make Clopidogrel less effective.

Question 38

What specific PPIs are of concern when used with Clopidogrel?

Answer 38

Evidence seems inconsistent, but omeprazole and esomeprazole are still of concern.

Question 39

Which PPI is considered safer to use with Clopidogrel?

Answer 39

Other PPIs such as lansoprazole should be okay.

Question 40

What is the common indication for both antiplatelet and anticoagulant therapy?

Answer 40

Patients often have indications for both antiplatelet (e.g. established cardiovascular disease) and anticoagulant (e.g. atrial fibrillation, venous thromboembolism or valvular heart disease) therapy.

Question 41

What is the risk associated with combination antiplatelet and anticoagulant therapy?

Answer 41

Combination therapy increases the risk of bleeding and may not be needed in all cases.

Question 42

What is recommended for secondary prevention of stable cardiovascular disease with an indication for an anticoagulant?

Answer 42

All patients are recommended to be prescribed an antiplatelet. If an indication for anticoagulant exists, anticoagulant monotherapy is indicated without the addition of antiplatelets.

Question 43

What is the treatment approach for patients post-acute coronary syndrome/percutaneous coronary intervention?

Answer 43

Patients are generally given triple therapy (2 antiplatelets + 1 anticoagulant) for 4 weeks-6 months after the event, followed by dual therapy (1 antiplatelet + 1 anticoagulant) to complete 12 months.

Question 44

What should be considered for patients with venous thromboembolism (VTE) who are on antiplatelets?

Answer 44

If a patient on antiplatelets develops a VTE, they are likely to be prescribed anticoagulants for 3-6 months. An ORBIT score should be calculated.

Question 45

What should be done for patients with different bleeding risk levels after developing VTE?

Answer 45

Those with a low risk of bleeding may continue antiplatelets. In patients with an intermediate or high risk of bleeding, consideration should be given to stopping the antiplatelets.