Plavix (generic name clopidogrel) is the second top-selling drug in the world (behind the cholesterol-lowering drug Lipitor), and is prescribed to prevent heart attacks and strokes. Clopidogrel is an anti-clotting medication called a platelet inhibitor. Platelets are small, irregularly shaped cell fragments found in the blood. Platelets help your body stop bleeding by sticking together to form a clot. But too many platelets in the blood can form unwanted and dangerous clots. These clots can block blood vessels in the heart, causing a heart attack, or in the brain, resulting in a stroke. They can also cause a blockage in the lung, called a pulmonary embolism. ?id=39" Anti-clotting drugs inhibit the ability of platelets to clump together to form clots.

Heart attacks and strokes are the two top causes of death worldwide, and strokes are a leading cause of adult disability. Another 15% of sudden deaths are caused by pulmonary embolism. These sobering statistics underline the importance of prescribing anti-clotting medication as a preventative measure for persons who have experienced a heart attack or stroke, or who suffer from heart disease or poor blood circulation due to hardened and narrowed arteries (atherosclerosis).

The risk of developing blood clots is higher in people who have had a recent heart attack or heart surgery (such as a valve replacement or the insertion of a stent), or who have an abnormal heart rhythm (atrial fibrillation). Extended periods of inactivity also increase the risk, as can genetic or disease-related difficulties with the blood's clotting ability.

In one large study, Plavix (clopidogrel) prescription medication was more effective than the often recommended aspirin in reducing heart attacks. The tolerability and frequency of side effects of clopidogrel were similar to that of aspirin, but the incidence of stomach and intestinal bleeding was less.

Another study underlined just how important it is that heart patients who have stents implanted to keep an artery open start taking ?id=39" anti-clotting medicines immediately.  One in six people in the study ignored their doctors' orders to start the blood thinning drug Plavix right away, and were found to be at almost twice the risk for a heart attack or death as those who took their doctor's advice.

Plavix must change to an active form in your body in order to be effective.  Some people (known medically as CYP2C19 poor metabolizers) don't change clopidogrel to its active form in their body as well as others. The medication doesn't work as well for them, leaving them at higher risk of heart attack or stroke. There are tests available to identify poor clopidogrel metabolizers – talk to your doctor about whether you should be tested if you are prescribed Plavix.