Clopidogrel

Question 1

Drug class?

Answer 1

Anti-platelet agent

Question 2

How does it work?

Answer 2

Clopidogrel is a prodrug, one of whose metabolites is an inhibitor of platelet aggregation. Clopidogrel must be metabolised by CYP450 enzymes to produce the active metabolite that inhibits platelet aggregation. The active metabolite of clopidogrel selectively inhibits the binding of adenosine diphosphate (ADP) to its platelet P2Y12 receptor and the subsequent ADP-mediated activation of the glycoprotein GPIIb/IIIa complex, thereby inhibiting platelet aggregation.

Question 3

Indications?

Answer 3

• Patients suffering from myocardial infarction (from a few days until less than 35 days), ischaemic stroke (from 7 days until less than 6 months) or established peripheral arterial disease.
• Patients suffering from acute coronary syndrome:
- Non-ST segment elevation acute coronary syndrome (unstable angina or non-Q-wave myocardial infarction), including patients undergoing a stent placement following percutaneous coronary intervention, in combination with acetylsalicylic acid (ASA).
- ST segment elevation acute myocardial infarction, in combination with ASA in medically treated patients eligible for thrombolytic therapy.

Prevention of atherothrombotic and thromboembolic events in atrial fibrillation.
- In adult patients with atrial fibrillation who have at least one risk factor for vascular events, are not suitable for treatment with Vitamin K antagonists and who have a low bleeding risk, clopidogrel is indicated in combination with ASA for the prevention of atherothrombotic and thromboembolic events, including stroke.

Question 4

Cotra-indications?

Answer 4

• Hypersensitivity to the active substance.
• Severe liver impairment.
• Active pathological bleeding such as peptic ulcer or intracranial haemorrhage.

Question 5

Side effects?

Answer 5

Vascular disorders - Haematoma
Respiratory, thoracic and mediastinal disorders - Epistaxis
Gastrointestinal disorders - Gastrointestinal haemorrhage, diarrhoea, abdominal pain, dyspepsia.
Skin and subcutaneous tissue disorders - Bruising
General disorders and administration site conditions - Bleeding at puncture site.

Question 6

Possible interactions?

Answer 6

P450!!!!

Oral anticoagulants: the concomitant administration of clopidogrel with oral anticoagulants is not recommended since it may increase the intensity of bleedings
Glycoprotein IIb/IIIa inhibitors: clopidogrel should be used with caution in patients who receive concomitant glycoprotein IIb/IIIa inhibitors
Acetylsalicylic acid (ASA): A pharmacodynamic interaction between clopidogrel and acetylsalicylic acid is possible, leading to increased risk of bleeding.
Clopidogrel should be used with caution in patients using the proton pump inhibitors omeprazole and esomeprazole.