COMMIT-CCS2 logo ClOpidogrel and Metoprolol in Myocardial Infarction Trial
FACT SHEET 4
Clopidogrel
What is clopidogrel?
Clopidogrel, first introduced in 1998, is one of a class of drugs known as anti-platelets. Anti-platelets reduce the tendency of platelets - cells in the blood that are vital for the normal clotting process - from sticking together and forming potentially dangerous clots. Thus they help in allowing the blood to flow freely.
Aspirin (the drug given alongside clopidogrel in COMMIT/CCS-2), is also an anti-platelet but it works via a different mechanism.
What conditions does clopidogrel treat?
Clopidogrel is suitable for thrombotic conditions; that is, conditions involving the formation of blood clots, or the risk of blood clot formation. These include:
  • ischaemic heart disease
  • acute coronary syndrome (a group of conditions that occur when the heart muscle does not receive enough oxygen-rich blood), the most frequent being a clot that forms on existing build up of plaque or cholesterol on the artery wall or unstable angina
  • ischaemic stroke (the most common type of stroke, which is due to a clot obstructing the blood vessels in the brain)
  • peripheral artery disease (poor circulation in the legs cased by narrowing of the arteries)
Who takes this drug?
Patients who:
  • have a history of recent heart attack
  • recent ischaemic stroke
  • established peripheral artery disease
  • have unstable angina either being managed medically or through PCI (balloon angioplasty - a procedure to improve the blood supply through a coronary artery).
How is it taken?
It is normally taken as a tablet (75 mg) once a day. Sometimes it can also be started with an initial 300 mg (or higher) 'loading' dose in order to achieve a more rapid anti-platelet effect.
Is clopidogrel used as emergency treatment?
Clopidogrel is becoming increasingly used as long-term therapy for unstable angina or during coronary artery procedures (such as PCI or stenting), but its use during a heart attack is low, presumably because there has been no clear evidence about the balance of benefits and risks in this setting. COMMIT/CCS-2 was designed specifically to assess its effectiveness in cutting deaths and the risk of repeat heart attacks in the immediate aftermath of a heart attack.