En Español
Make a difference. Volunteer for a Clinical Trial
Find A...
Resources:
This website is accredited by Health On the Net Foundation. Click to verify.We comply with the HONcode standard for trustworthy health information:
verify here
Aspirin: a humble miracle worker STORY BY

Anissa Anderson Orr

Aspirin relieves fever, muscle pain and headaches, prevents some heart attacks and strokes and may even help prevent Alzheimer’s.

And, in light of recent concerns over cousin-drugs like ibuprofen and naproxen and the outright removal of Vioxx and Bextra from the market, the humble little aspirin is enjoying renewed attention.

So what makes this, “wonder drug that works wonders,” so wonderful? Can a drug that’s been around for thousands of years really be as good as—and safer than—newer prescription medications?

“I am still captivated by aspirin. I have been since I was a kid and it was just for reducing fever then,” says Dr. Lenard M. Lichtenberger, professor in the Department of Integrative Biology & Pharmacology at The University of Texas Graduate School of Biomedical Sciences at Houston. Lichtenberger has spent much of his career studying aspirin. “I believe that aspirin deserves all the credit that it receives.”

Barking Up the Right Tree

Hipprocates, the father of modern medicine, used ground willow tree bark to ease aches and pains way back in the fifth century. Willow bark contains the chemical salicin, or salicylic acid.

By the late 1800s, salicylic acid became the standard drug to treat arthritis. However, it was very harsh and irritated the stomach. Felix Hoffmann, a German chemist with Friedrich Bayer and Company, synthesized acetylsalicylic acid (ASA) in 1897 as a treatment for his father's arthritis. The synthesized form of the drug didn’t hurt the stomach as much and was better at treating pain. By 1899, The Bayer Company was providing aspirin to physicians to give to their patients.

Why Aspirin Works

After all these years, experts still are not exactly sure how it works. The most widely accepted theory is that aspirin helps reduce the level of chemicals in the blood called prostaglandins. Prostaglandins cause pain by stimulating the muscles to contract and blood vessels to dilate. Aspirin stops the prostaglandins from forming by blocking an enzyme called cyclooxygenase 2 or COX-2. Aspirin is the first known COX-2 inhibitor, and the first of a class of drugs called non-steroidal anti-inflammatory drugs (NSAIDs).

The downside is that aspirin also blocks the COX-1 enzyme which helps protects the lining of the stomach. As a result, aspirin can increase the risk for gastrointestinal bleeding and ulcers.

Over the past few decades, researchers have developed new NSAIDS. General NSAIDS like ibuprofen (Advil and Motrin) and naproxen (Aleve) block both COX-1 and COX-2 and are available over the counter. To better protect the stomach, even more targeted NSAIDS, called COX-2 inhibitors were developed to block only the COX-2 enzyme. But two of these drugs, Vioxx and Bextra were taken off the market earlier this year because of increased risk of heart attack and stroke.

Acetaminophen (Tylenol) is a separate class of pain relievers and fever reducers, and is gentler on the stomach than NSAIDS but boasts no anti-inflammatory properties.

Heart Disease and Aspirin

Because aspirin is so safe, doctors say taking it daily or every other day is an easy way for most people older than age 40 to protect their hearts. The U.S. Preventive Services Task Force recommends that men age 40 and older, women who are past menopause and younger people with risk factors for heart attack or stroke, such as diabetes or smoking, discuss aspirin therapy with their doctors.

“Aspirin is very inexpensive, it not only relieves pain and fever but has an anti- inflammatory effect,” says cardiologist Dr. Samuel W. Casscells, the John Edward Tyson Distinguished Professor of Medicine at the UT Houston Medical School. “Aspirin and aspirin only prevents blood clots. Aspirin’s cousins, such as NSAIDS or COX-2 inhibitors, don’t prevent blood clots.”

The U.S. Food and Drug Administration approved in 1985 the use of aspirin to prevent heart attacks in patients who had either suffered a previous heart attack or suffered from unstable angina. The decision was based on evidence that aspirin reduced the risk of a second heart attack by 20 percent. For patients suffering from unstable angina, the risk of a heart attack decreased by 51 percent.

The most effective dosage of aspirin is still a matter of contention, although most doctors recommend the lowest dose possible to minimize side effects. Doses range from one-quarter of a baby aspirin to full adult doses, depending on its medical purpose and your doctor’s recommendations.

Aspirin’s role in preventing heart attacks has not been studied as much in women. The Women’s Health Initiative, a randomized study of 40,000 women between the ages of 45 and 65, found that low dose aspirin did not prevent first heart attacks or cardiovascular events in the total group of women studied.

However, for women older than 65 in the study, aspirin reduced the risk of major cardiovascular events by 26 percent.

Stroke and Aspirin

Aspirin has also been shown to help reduce the risk of ischemic stroke (a result of a clot blocking an artery in the brain) which is also the most common kind of stroke. And in some cases, aspirin may work better at preventing stroke in high-risk patients than more sophisticated anti-clotting drugs.

“People at risk of developing ischemic strokes should consider aspirin instead of warfarin, a common anti-clot drug,” says Dr. James Grotta, professor of neurology at the medical school and director of the stroke program at Memorial Hermann Hospital.

In a study of 569 people, patients on warfarin (Coumadin), suffered a higher death rate and had more bleeding compared to those who took aspirin. Results of the study appeared in the March 31 issue of the New England Journal of Medicine.

Aspirin reduced the risk of ischemic stroke in women who took low-dose aspirin by 24 percent, according to the Women’s Health Initiative study. It also has shown some promise in preventing a variety of diseases and health conditions ranging from Alzheimer’s disease to colon cancer.

Not for Everyone

Aspirin is not without some risks.

“If you think you are having a stroke call 9-1-1, don’t take an aspirin,” Grotta says. Some strokes are caused by bleeding in the brain and aspirin may make it worse, he says. “You don’t want to take aspirin until you know it is not a bleeding stroke.”

The bottom line? Carefully weigh the risks and benefits of aspirin and any risk factors you may have before starting aspirin therapy.

Improving a Miracle

While researchers continue to uncover new ways to use aspirin, others are working hard to improve it. Lichtenberger has developed a patented process that binds aspirin with phosphatidylcholine (PC), a purified form of lecithin derived from soybeans. The PC-aspirin protects the lining of the stomach. But unlike currently used enteric coatings, it is easily dissolved, allowing the aspirin to cross into the bloodstream more quickly.

“Every few months I get surprised by another new application for aspirin,” Lichtenberger says. “But I think another area of interest that we are pursuing is reducing the side effects of aspirin and getting a much better understanding of NSAIDS and how they act, with the hope that we can further improve the drug’s cardioprotective actions.”

He hopes protecting the stomach may make aspirin a more palatable option for people prone to gastrointestinal bleeds, but also at high risk for heart attack. Such a development would be more than welcome by doctors like Casscells, looking for a safe and effective drug to prescribe their patients.

“Aspirin is still a miracle drug,” Casscells says. “Number one: the other more expensive drugs don’t prevent blood clots. Number two: we’ve had it for 100 years, and it is a natural compound from tree bark. These reasons give you great comfort when prescribing aspirin.”

Last Updated: 6-15-2005