Antiplatelet drugs

Notes:

1. Enteric-coated aspirin tablets are not recommended. There is no convincing evidence that at a daily dose of 75 mg using enteric-coated rather than soluble aspirin reduces the risk of gastrointestinal bleeding. (Ref: DTB Jan 1997 p7-8).
2. The use of clopidogrel with low dose aspirin is recommended for up to 1 year after acute coronary syndromes, up to 1 year after drug eluting stent insertion and up to 3 months after bare metal stenting and occasionally for longer at the discretion of the operator.
3. Current evidence demonstrates that after one year of clopidogrel with low dose aspirin, the risks of continued treatment outweigh the benefits.
4. See NICE CG 94 (March 2010) Unstable angina and NSTEMI and CG172: Secondary prevention in primary and secondary care for patients following a myocardial infarction Nov 2013 for further information.
5. Clopidogrel should NOT be substituted for aspirin, where patient has GI discomfort or bleed.  Gastroprotection with PPI should be considered (lansoprazole 15mg capsules).
6. Prasugrel (Efient®) is an antiplatelet agent with a similar mode of action to clopidogrel.
7. It is licensed for use in conjunction with aspirin for the prevention of atherothrombotic events in patients with acute coronary syndrome (i.e., unstable angina, non-ST segment elevation myocardial infarction [UA/NSTEMI] or ST segment elevation myocardial infarction [STEMI]) undergoing primary or delayed percutaneous coronary intervention (PCI).
8. In certain patient groups it has demonstrated superior efficacy to clopidogrel but at a cost of an increased risk of major bleeding.
9. It is administered as a 60mg loading dose with a maintenance dose of 10mg daily for up to 12 months. A 5mg daily maintenance dose is recommended for individuals weighing less than 60kg.
10. NICE TA 317 (July 2014): Prasugrel 10 mg in combination with aspirin is recommended as an option for preventing atherothrombotic events in adults with acute coronary syndrome (unstable angina [UA], non-ST segment elevation myocardial infarction [NSTEMI] or ST segment elevation myocardial infarction [STEMI]) having primary or delayed percutaneous coronary intervention.
11. Ticagrelor (Brilique®) is a new antiplatelet agent licensed for use in combination with aspirin to prevent atherothrombotic events after acute coronary syndrome.
12. In studies ticagrelor was found to be more effective at preventing further atherothrombotic events than clopidogrel but at the expense of an increased risk of bleeding and increased incidence of dypsnoea.
13. Initiation must be undertaken by a cardiologist. GPs may prescribe continuation of treatment on the advice of the specialist for up to 12 months.
14. NICE TA 260: Ticagrelor for the treatment of acute coronary syndromes (ACS) (Oct 2011) recommends that: 
    Ticagrelor in combination with low-dose aspirin is recommended for up to 12 months as a treatment option in adults with acute coronary syndromes (ACS) that is, people:
    • with ST-segment-elevation myocardial infarction (STEMI) – defined as ST elevation or new left bundle branch block on electrocardiogram – that cardiologists intend to treat with primary percutaneous coronary intervention (PCI)
    • with non-ST-segment-elevation myocardial infarction (NSTEMI)
    • admitted to hospital with unstable angina – defined as ST or T wave changes on electrocardiogram suggestive of ischaemia plus one of the characteristics defined in section 1.2. 
    Before ticagrelor is continued beyond the initial treatment, the diagnosis of unstable angina should first be confirmed, ideally by a cardiologist.
15. Ticagrelor has a twice daily dosage regime.

16. NICE TA 210: Clopidogrel and modified release dipyridamole for the prevention of occlusive vascular events (review of TA 90) (Dec 2010)

NICE has recommended that:

Clopidogrel is an option to prevent occlusive vascular events:

The combination of MR dipyridamole and aspirin is used as part of the prevention of occlusive vascular events in people who have had

Modified release dipyridamole alone is an option to prevent occlusive vascular events

MHRA Drug Safety Update – Interaction between the use of clopidogrel and PPI’s – April 2010

In light of the most recent evidence, the previous advice on the concomitant use of clopidogrel with proton pump inhibitors has now been modified. Use of either omeprazole or esomeprazole with clopidogrel should be discouraged. The current evidence does not support extending this advice to other PPIs.