In general, aspirin has been recommended for patients in the following categories:

• Patients who have had a mini-stroke (transient ischemic attack) and/or ischemic strokes

Furthermore, patients who are scheduled for procedures to open blocked arteries (e.g., angioplasty, stenting) may benefit from “super aspirins,” which are given intravenously during cardiac interventional procedures. For these patients, treatment with “super aspirins” may significantly cut the risk of death or other major complications. People who cannot tolerate aspirin may be given a different antiplatelet called clopidogrel, which is also given to people undergoing catheter-based procedures. For those who can take aspirin, studies have shown that aspirin and clopidogrel, given together, have an enhanced effect in inhibiting clot formation. The aspirin/clopidogrel combination has also demonstrated benefit in individuals at risk for acute coronary events (e.g., those with unstable angina).

Though the findings are promising, aspirin is not for everyone. The best course of therapy begins with a physical examination and regular medical visits, as well as with a healthy lifestyle. Aspirin therapy works best with individuals whose blood pressure, cholesterol and weight levels are within normal ranges. Physicians will often advise patients not to take aspirin if they have certain pre-existing medical conditions. In general, the following people are usually advised against taking aspirin:

• Pregnant women, especially during the first and third trimesters. Aspirin can prolong or otherwise complicate delivery.
  
  
• People who are about to have surgery. Aspirin can promote excessive bleeding, and most surgeons request that their patients refrain from taking aspirin for several (generally 10) days before surgery.
  
  
• Children under 18 who are recovering from chickenpox or the flu. Aspirin has been linked to a rare, potentially fatal disease called Reye syndrome.
  
  
• Heavy drinkers (three or more drinks per day). Aspirin has been linked to stomach irritation, liver damage and excessive bleeding in such people.
  
  
• People with chronic intestinal problems, including ulcers, gastritis, inflammatory bowel disease (e.g., Crohn's disease, ulcerative colitis) and bleeding conditions.
  
  
• People taking certain blood thinning medication. Many patients can be safely treated with anticoagulants and low-dose aspirin.
  
  
• People with allergies to some medications, including aspirin.
  
  
• People with uncontrolled high blood pressure (hypertension).

A recent study discovered that a small percentage of people may be “resistant” to aspirin’s anti-clotting effects. These individuals (about 5 percent of the study participants) had triple the risk of heart attack and stroke. Researchers are working on methods to determine which patients are resistant to aspirin, as well as alternative medication therapy. The anti-platelet clopidogrel may be considered among these patients.

For individuals with no history or significant risk of heart disease, the evidence indicates that aspirin’s best medical benefit is limited to temporary pain relief. Such “low-risk” individuals should explore with their physician if the risks associated with taking aspirin outweigh its potential benefits.