Clopidogrel

How does it work?

Plavix tablets contain the active ingredient clopidogrel hydrogen sulphate, which is a type of medicine called an antiplatelet (sometimes referred to as a 'blood-thinning' medicine). It stops blood cells called platelets from clumping together and forming blood clots. Clopidogrel is also available without a brand name, ie as the genericmedicine.

Clopidogrel works by preventing a natural substance called adenosine diphosphate (ADP) from binding to its receptors on platelets. ADP is one of the chemicals in the body that cause platelets to clump together and start the process of blood clotting. As clopidogrel stops ADP from binding to platelets, it reduces the likelihood of clots forming in the blood.

A blood clot that forms inside the blood vessels is known as a thrombosis and can be dangerous, as it can cause a blockage that cuts off the blood supply to an organ. A blockage in the arteries supplying blood to the heart or brain can cause a heart attack or stroke. A blockage in the blood vessels in the extremities, eg legs, may result in gangrene.

Blood clots and blockages mainly result from a build up of atherosclerosis on the inside of blood vessels. Atherosclerosis is a build up of cholesterol and fat cells that narrows the blood vessels and makes their interiors rough and bumpy. This makes it more difficult for blood to flow through the vessels, and increases the likelihood of clots forming in the vessels.

People who have already suffered a heart attack or stroke are at risk of having another because of the atherosclerosis in their arteries. People with unstable angina are also at risk of a heart attack because of the atherosclerosis in their arteries. Similarly, people who have narrowed arteries in their extremities, eg legs (peripheral arterial disease), are also at risk of blood clots. These events are known as atherothrombotic events.

Clopidogrel is used to prevent blood clots forming within blood vessels, and therefore reduce the risk of further atherothrombotic events in these groups of people.

Side effects

Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.