Aspirin is commonly used in low dosages (75mg per day) in patients with Coronary Artery Disease (hardening or narrowing of the heart arteries). It works by making small particles (platelets) in the blood less “sticky”. As a result the platelets are less likely to clump together and block a heart artery causing a heart attack. Aspirin is used in a similar way in the treatment of mini-strokes. Clopidogrel works in a different way on the platelets but has similar benefits. Taken together the benefits are additive. Unfortunately so are the side effects. Patients who have had a stent placed in one of their heart arteries during an angioplasty procedure are usually treated with both drugs for up to one year after the procedure. At that time clopidogrel is usually stopped but aspirin is continued indefinitely.