Patient on anti-platelet therapy

Question 1

What are anti-platelet drugs?

Answer 1

Decrease platelet aggregation and inhibit thrombus formation in the arterial circulation, because in faster-flowing vessels, thrombi are composed mainly of platelets with little fibrin

Question 2

Give examples of anti-platelets

Answer 2

• Aspirin
• Clopidogrel
• Dipyridamole
• Prasugrel
• Tricagrelor
• Cangrelor (to be used under expert supervision only)

Question 3

How does aspirin work?

Answer 3

Inhibits COX 1 and 2, hence blocking thromboxane A2 synthesis and reducing platelet aggregation

Question 4

What is aspirin used for?

Answer 4

Long-term use of low-dose aspirin is recommended in patients with established cardiovascular disease (secondary prevention)- it is not recommended for primary prevention of CVD
Examples:
- Following coronary bypass surgery
- Intermittent claudication
- Stable angina
- Acute coronary syndromes
- Following placement of coronary stents
- Stroke

Question 5

When is aspirin monotherapy indicated?

Answer 5

Following transcatheter aortic valve implantation

Question 6

Following transcatheter aortic valve implantation, aspirin monotherapy is indicated- what do you do if it is not tolerated?

Answer 6

Use clopidogrel instead

Question 7

How does clopidogrel work?

Answer 7

(P2Y12 receptor anatgonist)
- Inhibits activation of platelets

Question 8

What is clopidogrel used for?

Answer 8

Prevention of atherothrombotic events in patients with a history of symptomatic ischaemic disease (e.g. ischaemic stroke)

Question 9

When is clopidogrel used in combination with low-dose aspirin?

Answer 9

For the prevention of atherothrombotic and thromboembolic events in patients with atrial fibrillation- use of clopidogrel and aspirin increased bleeding risk

Question 10

When is clopidogrel monotherapy indicated?

Answer 10

When aspirin is contraindicated e.g aspirin hypersensitivity, or aspirin not tolerated despite addition of PPI (pt at high risk of GI bleeding)

Question 11

What is Dipyridamole liscensed for?

Answer 11

Secondary prevention of ischaemic stroke and transient ischaemic attacks

Question 12

What is Prasugrel licensed for?

Answer 12

Prevention of atherothrombotic events in patients with acute coronary syndrome undergoing percutaneous coronary intervention; the combination is usually given for up to 12 months

Question 13

What is Ticagrelor licensed for?

Answer 13

(P2Y12 receptor antagonist)
Prevention of atherothrombotic events in patients with acute coronary syndrome; the combination is usually given for up to 12 months

Question 14

What do patients selected for PCI with the placement of a coronary stent require?

Answer 14

Dual antiplatelet therapy with aspirin and either cangrelor, clopidogrel, prasugrel or ticagrelor- aspirin therapy should continue indefinitely

Question 15

What is recommended following PCI for stable angina with placement of drug-eluting stent?

Answer 15

Clopidogrel in addition to aspirin for at least 6 months (and for at least 1 month is bare-metal stent)- clopidogrel should noy be discontinued prematurely cos risk of stent thrombosis

Question 16

What are Glycoprotein IIb/IIIa inhibitors?

Answer 16

Prevent platelet aggregation by blocking the binding of fibrinogen to receptors on platelets

Question 17

What are some examples of Glycoprotein IIb/IIIa inhibitors?

Answer 17

1. Eptifibatide- (and tirofiban) prevent early myocardial infarction in patients with unstable angina or non-ST-segment-elevation myocardial infarction
2. Tirofiban- for the reduction of major cardiovascular events in patients with ST-segment elevation myocardial infarction intended for primary percutaneous coronary intervention
3. Abciximab- prevention of ischaemic complications in pt undergoing percutaneous transluminal coronary intervention