Antiplatelet drugs

Question 1

Antiplatelet drugs decrease platelet aggregation and inhibit thrombus formation in the arterial circulation, Explain why

Answer 1

In faster-flowing vessels, thrombi are composed mainly of platelets with little fibrin

Question 2

Is aspirin recommended for primary prevention of cardiovascular disease, in patients with or without diabetes, or hypertension?

Answer 2

Not recommended for primary prevention

Question 3

when is low-dose aspirin recommended to be used long term?

Answer 3

In patients with established cardiovascular disease (secondary prevention)

Question 4

Can aspirin be initiated in those with high blood pressure?

Answer 4

unduly high blood pressure must be controlled before aspirin is given

Question 5

what can be given to patient at a high risk of GI bleeding if aspirin is to be initiated for long term prevention?

Answer 5

A proton pump inhibitor can be added

Question 6

What cardiovascular conditions should aspirin be used in? (6)

Answer 6

1) Following coronary bypass surgery
2) Atrial fibrillation
3) Intermittent claudication
4) Stable angina and acute coronary syndromes,
5) Following placement of coronary stents
6) Stroke

Question 7

When can clopidogrel be used for the prevention of atherothrombotic events?

Answer 7

If they have a history of symptomatic ischaemic disease (e.g. ischaemic stroke)

Question 8

How long should clopidogrel be given in combination with aspirin for the prevention of atherothrombotic events in :

1) Non-ST elevation acute coronary syndromes
2) ST elevation acute coronary syndromes

Answer 8

1) Non-ST elevation ACS : Initially 300 mg, then 75 mg daily for 3 months (but up to 12 months)
2) ST elevation ACS: Initially 300 mg, then 75 mg for at least 4 weeks

Question 9

when would clopidogrel be licenced to be prescribed for the prevention of atherothrombotic and thromboembolic events in patients with AF?

Answer 9

It would be prescribed with low-dose aspirin if both of the following criteria were met:

1) At least one risk factor for a vascular event
2) Warfarin is unsuitable

Question 10

when would clopidogrel monotherapy be considered in patients as secondary prevention?

Answer 10

1) When aspirin is contra-indicated e.g. Aspirin hypersensitivity
2) Aspirin is not tolerated despite the addition of PPI

Question 11

what is dipyridamole licenced to treat? (2)

Answer 11

1) adjunct to oral anticoagulation for prophylaxis of thromboembolism associated with prosthetic heart valves
2) M/R used for secondary prevention of ischaemic stroke and TIA’s

Question 12

Prasugrel, in combination with aspirin is licenced to treat which condition and for how long should it be given?

Answer 12

1) Prevention of atherothrombotic events in patients with ACS undergoing percutaneous coronary intervention
2) up to 12 months

Question 13

Ticagrelor is licensed for the prevention of atherothrombotic events in patients with ACS. How many months should it usually be given for?

Answer 13

up to 12 months in combination with aspirin

Question 14

What is a percutaneous coronary intervention?

Answer 14

non-surgical procedure that uses a catheter to place a stent to open up blood vessels in the heart that have been narrowed by atherosclerosis

Question 15

what medications need to be prescribed to those

selected for a percutaneous coronary intervention?

Answer 15

Dual antiplatelet therapy with aspirin and either cangrelor, clopidogrel, prasugrel, or ticagrelor

Question 16

Clopidogrel + aspirin is recommended following percutaneous coronary intervention in those with stable angina. How long should treatment be continued for the following stents?

1) Bare-metal stent
2) Drug-eluting stent

Answer 16

1) Bare-metal stent: At least 1 month

2) Drug-eluting stent: At least 6 months

Question 17

Why should clopidogrel not be discontinued prematurely in patients with a drug-eluting stent?

Answer 17

There is an increased risk of stent thrombosis as a result of the eluted drug slowing the re-endothelialisation process.

Question 18

list 3 Glycoprotein IIb/IIIa inhibitors and explain the MoA of these drugs

Answer 18

1) Abciximab, Eptifibatide, Tirofiban

2) prevent platelet aggregation by blocking the binding of fibrinogen to receptors on platelets

Question 19

Abciximab it is licensed as an adjunct to heparin (unfractionated) and aspirin for the prevention of ischaemic complications in high risk patients. Why should it only be given once daily?

Answer 19

To avoid additional risk of thrombocytopenia

Question 20

what is the MoA of Apixiban?

Answer 20

Direct inhibitor of activated factor Xa

Question 21

Apixiban is indicated for the prophylaxis of stroke and systemic embolism in non-valvular AF with at least one risk factor. List some of the risk factors that would be suitable

Answer 21

1) previous stroke or transient ischaemic attack
2) symptomatic heart failure
3) Diabetes mellitus
4) Hypertension
5) Age 75 years and over

Question 22

When should the dose of apixiban be reduced to 2.5mg BD?

Answer 22

least two of the following characteristics:
1) Age 80 years and over
2) Body-weight less than 61 kg
3) SCr 133 micromol/litre and over.
↳ (Reduce dose to 2.5mg BD if CrCl 15-29ml/min)