Low-Dose ASA Therapy
Topic Overview
Why take low-dose ASA?
Good old ASA, the common pain reliever that has been in our medicine cabinets for almost a century, also has a talent for prevention. ASA (such as Aspirin) has been proven to prevent a first and second heart attack in people who have coronary artery disease.1 When taken during and after a heart attack, ASA can reduce your chances of dying.2 It also reduces the risk of having a stroke in those who have had a previous stroke or a transient ischemic attack (a temporary interruption of blood flow to the brain), which is often a warning sign of an impending stroke.3
Who should take low-dose ASA?
Some experts recommend that the following people consider taking an ASA a day to prevent heart problems:
- People who are at high risk for coronary artery disease or who already have coronary artery disease
- Healthy men over age 40 who have one or more risk factors for heart disease, as long as their blood pressure is controlled and the benefit of ASA is greater than the risks
- Healthy women over age 65, or women over 65 who have one or more risk factors for heart disease, as long as their blood pressure is controlled and the benefit of ASA is greater than the risks
Also, if you have had a clot-related stroke or transient ischemic attack, your health professional will probably recommend that you take an ASA daily. ASA protects you from having a clot-related stroke in the same way it protects you from having a heart attack.
ASA slows the blood's clotting action by reducing the clumping of platelets. Platelets are cells that clump together and help to form blood clots. ASA keeps platelets from clumping together, thus helping to prevent or reduce blood clots.
During a heart attack, blood clots form in an already-narrowed artery and block the flow of oxygen-rich blood to the heart muscle (or to part of the brain, in the case of stroke). When taken during a heart attack, ASA slows clotting and decreases the size of the forming blood clot. Taken daily, ASA's anti-clotting action helps prevent a first or second heart attack.
ASA should not be taken if you think you are having a stroke, because not all strokes are caused by clots. ASA could make some strokes worse.
Should I take ASA?
Daily ASA is not right for everyone. Don't start taking ASA regularly without talking to your health professional first. ASA's anti-clotting action can cause unwanted side effects such as stomach bleeding and bleeding in the brain. People who have stomach ulcers, a history of gastrointestinal bleeding, blood-clotting disorders, uncontrolled high blood pressure, and liver or kidney disease may need to avoid ASA.
ASA should not be taken by people who are at risk for or who have had a hemorrhagic stroke, which is a type of stroke that is not caused by a blood clot but rather by bleeding into and around the brain.
ASA can trigger asthma attacks in some people who have a sensitivity to it.
Also, don't take ASA without first talking to your health professional if you're already taking prescribed blood thinners, such as Coumadin. The combined effect could cause bleeding problems.
What should I avoid when taking low-dose ASA therapy?
Drinking 3 or more alcoholic drinks every day while taking daily ASA increases your risk for liver damage and stomach bleeding. If your health professional recommends ASA, limit or stop alcohol usage.
ASA should not be taken with many prescription and over-the-counter drugs, vitamins, herbal remedies, and supplements. Talk to your health professional about all the drugs and other remedies you take before starting ASA therapy.
Because ASA reduces your blood's ability to clot, your health professional may want you to stop taking ASA at least 5 days before any surgery or dental procedure that may cause bleeding. Don't suddenly stop taking ASA without talking to your health professional first.
Tell your health professional if you notice that you bruise easily, have bloody or black stools, or have prolonged bleeding from cuts or scrapes.
Although non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen and naproxen, relieve pain and inflammation much like ASA does, they do not affect blood clotting in the same way as ASA. Do not substitute NSAIDs for ASA because they will not decrease your risk of another heart attack.
In fact, some research indicates that taking ibuprofen regularly seems to inhibit ASA's ability to prevent a first heart attack. (Intermittent NSAID use did not interfere.4) Talk to your health professional about this interaction if you require long-term ibuprofen therapy. Most health professionals recommend taking ASA at least two hours before ibuprofen to reduce the likelihood of an interaction.
Exactly how much ASA should I take?
This is where it gets confusing. ASA comes in a wide range of dosages and in many forms. The best dose of ASA has not been established. Your health professional can provide the correct directions for use. Using ASA correctly gives you the best chance of getting the greatest benefits with the fewest unwanted side effects.
Some health professionals recommend taking low-dose ASA (at least 75 mg/day), because a low dose seems to be as effective in preventing heart attacks as higher doses and has fewer side effects. One low-dose ASA contains 81 mg; one regular-strength ASA contains about 325 mg. Some health professionals recommend taking 100 mg every other day. Take ASA with food if it bothers your stomach.
Also, some drug companies combine ASA with other ingredients, such as caffeine and sodium. These formulas should not be used for daily ASA therapy.
Does ASA have other benefits?
Early studies suggest that ASA may reduce the risk of Alzheimer’s disease. However, more research is needed before doctors begin recommending ASA to prevent Alzheimer's disease.
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| Author: | Douglas Dana Robin Parks, MS | Last Updated: September 21, 2007 |
| Medical Review: | Anne C. Poinier, MD - Internal Medicine Caroline S. Rhoads, MD - Internal Medicine Stephen Fort, MD, MRCP, FRCPC - Interventional Cardiology Robert A. Kloner, MD, PhD - Cardiology Ruth Schneider, MPH, RD - Diet and Nutrition | |
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