HEALTHAspirin, the wonder drug: It's not just for headaches anymoreThe original miracle cure is still an essential element of the formulary. New studies are looking at aspirin's power to fight colon cancer, Alzheimer's disease and diabetes.By Susan J. Landers, amednews staff. July 22, 2002. As newer -- and more expensive -- challengers are unleashed by the pharmaceutical industry, aspirin continues to hold its own and to excite researchers intent upon exploring its curative powers for a variety of humanity's harshest ills. Wait. What's going on here? Is it possible the little bottle of pills in medicine cabinets for decades can do so much more than chase away headaches? "I am a great believer in taking aspirin, but not just willy-nilly," said Thomas Bryant, MD, 60, who takes a quarter of a standard 325-mg tablet every day. (The equivalent of a low-dose aspirin at lower cost.) It's not surprising Dr. Bryant is a booster of aspirin, considering he calls himself "Dr. Aspirin" in honor of his post as president and chair of the Aspirin Foundation of America. The foundation is funded by about a half dozen manufacturers of the product and was established for public education rather than marketing, according to Dr. Bryant. Aspirin stood alone for thousands of years as the premier pain reliever. A derivative of the white willow tree's bark and leaves, it was prescribed by Hippocrates in 400 B.C. It has since been joined by other nonsteroidal anti-inflammatory drugs, or NSAIDs, such as ibuprofen. But the phrase, "Take two aspirin and call me in the morning," will probably always be a refrain in the medical profession.
Aspirin regimens cost about $1 per month.
Not that aspirin is without its challengers. The manufacturers of the new COX-2 inhibitors celecoxib, co-marketed by Pharmacia Corp. and Pfizer Inc. as Celebrex, and rofecoxib, marketed by Merck as Vioxx, contend the drugs can relieve pain without aspirin's harmful side effect of gastrointestinal complications. However, one of them has started to show some weaknesses. On June 7 the Food and Drug Administration ruled that Celebrex must carry a warning label stating that, like many other pain relievers, it too can cause serious ulcer complications. Celebrex's high price had also given pause to insurers. Another high-price aspirin challenger, the blood-thinner Plavix, made by Bristol-Myers Squibb Co., was found to work only "slightly better" than aspirin and not to be worth the extra cost, according to a study in the June 6 New England Journal of Medicine. At about $1 per month, aspirin certainly has the cost advantage over the $80-and-up price tags carried by Plavix and Celebrex. Aspirin is also going head-to-head with another blood thinner, warfarin, in a clinical trial to determine which is more effective in preventing strokes in patients with narrowing of one of the arteries in the brain. That study, which is still recruiting patients, is being funded by the National Institute of Neurological Disorders and Stroke.
Aspirin cuts the risk of heart disease by 28% in people with no previous heart attack or stroke.
It has been in the area of cardiovascular health that aspirin has made the most prominent of its recent advances. For example, the U.S. Preventive Services Task Force recommended earlier this year that physicians discuss the risks and benefits of aspirin therapy with their healthy patients who are at increased risk of coronary heart disease. Studies reviewed by the task force found regular aspirin use reduced the risk of coronary heart disease by 28% among people with no history of heart attack or stroke but who were at increased risk. Close observers believe the FDA won't be far behind in recommending aspirin be considered as a preventive measure in heart disease. The agency has already approved the use of aspirin to reduce the risk of stroke or heart attack among patients who have already had such attacks. The task force said the benefit of taking a daily, low-dose aspirin would outweigh the harm it might cause individuals with a 3% or greater risk of having a heart attack within the next five years. It also noted that there are several calculators available on the Internet to help patients assess their overall risk of heart disease. Roger Blumenthal, MD, director of preventive cardiology and associate professor of medicine and cardiology at Johns Hopkins University, favors using task force recommendations for certain patients. "We have good data that aspirin is helpful in people with known vascular disease or diabetes, but for asymptomatic people we generally reserve aspirin for individuals who are above a certain age and have another risk factor for heart disease."
Aspirin decreases the risk of colon cancer, adenomas and of death from cancer.
Dr. Blumenthal also points to a risk prediction formula developed by the long-running Framingham Heart Study as appropriate for assessments. "Most individuals over the age of 50 who have at least one other risk factor for heart disease would likely have a high enough Framingham risk score to at least warrant consideration of low-dose aspirin as a cardiovascular preventive modality," he said. Among the risk factors cited by the task force: men older than 40, postmenopausal women and younger people who have diabetes or hypertension. Dr. Blumenthal, 42, has assessed his risk and decided to take low-dose aspirin every other day. Beyond heartsWhile the evidence connecting aspirin and heart health mounts, a recently released study might prompt individuals at risk of colon cancer to consider taking a low-dose aspirin tablet each day. Results from a multicenter study found that participants who took one 80-mg aspirin a day reduced their risk of a recurrence of colon polyps by 19%. The findings were presented by John A. Baron, MD, professor of medicine at Dartmouth Medical School, Hanover, N.H., during the April meeting of the American Assn. for Cancer Research. Dr. Baron's findings carry particular weight as they build on a body of evidence that has been accumulating for 25 years, said Ernest Hawk, MD, MPH, chief of gastrointestinal cancer prevention at the National Cancer Institute. More that 100 animal studies show that aspirin and aspirin-like drugs decrease the risk of colon cancer and more than 30 epidemiological research projects show that there is about a 30% to 40% reduction in adenomas, cancer and cancer mortality among patients using aspirin, he said. The time is near, predicted Dr. Hawk, when primary care physicians will be able to recommend their patients at risk for colon cancer take a low-dose aspirin tablet each day. Still, having the published data to support verbal claims that the treatment is safe would add reassurance, said Dr. Hawk. "We always feel best when we have a couple of studies showing the same results," he said. Those additional studies are already under way. Robert Sandler, MD, a gastroenterologist at the University of North Carolina at Chapel Hill is heading a study to examine the effects of a daily 325-mg aspirin tablet on adults who have had prior colon cancer. A large British study will examine the effectiveness of aspirin and folic acid in preventing the recurrence of colorectal polyps. Aspirin's promise has also been seen in epidemiological studies involving cancers of the upper gastrointestinal area, said Dr. Hawk. There have been about 10 studies and almost all of them have shown protective effects against cancers. But in most other cancers, studies with aspirin have produced "a mixed bag" of results, he said. "There is also a fair amount of epidemiologic evidence to indicate that people who take lots of anti-inflammatory medications have less Alzheimer's' disease," said Bill Thies, PhD, vice president for medical and scientific affairs for the Alzheimer's' Assn. Plus, there is a body of basic science information that provides a plausible mechanism for the action of NSAIDs to prevent Alzheimer's, he noted. "The piece we're missing is the good clinical trial that says, 'If you intervene with aspirin you get less Alzheimer's' disease,' " said Dr. Thies. Dousing inflammationThere is a new clinical trial under way to test other anti-inflammatory drugs (but not aspirin) for their ability to prevent Alzheimer's disease. That study will be conducted at four locations and will test the ability of the drugs to reduce inflammatory processes in the brain associated with Alzheimer's disease. It is the anti-inflammatory property of aspirin that seems to be key to its effectiveness in such a range of diseases. "What aspirin really does is interfere with inflammation in the various prostaglandin metabolic systems," said Dr. Bryant. For example, aspirin's ability to reduce the inflammation in blood vessels was recently reported to be another reason for those with heart disease to take aspirin. Findings in the May 14 Circulation, the American Heart Assn. journal, suggest that, in addition to its long-known blood-thinning properties, aspirin might also provide protection from inflammation, thus offering additional benefits. "Aspirin is widely used to prevent heart attacks and strokes, but it is assumed that its effects are solely attributable to its blood-thinning actions," noted Patrick J.T. Vallance, MD, the author of the study and a professor of clinical pharmacology at University College London. "But our research turns the clock back on aspirin, and suggests that some of aspirin's effects really are due to its anti-inflammatory properties, which people have known about for 100 years or more," he said. And the new aspirin revelations continue. In June, researchers examining aspirin and diabetes presented findings at the American Diabetes Assn.'s annual scientific meeting that links inflammation to type 2 diabetes. "In the past year, about six studies have shown that markers of inflammation predict development of type 2 diabetes," said Joshua Barzilay, MD, a pediatrician at Kaiser Permanente of Georgia. However, though it sometimes may seem aspirin is the newest wonder drug, its dangers can't be overlooked. A meta-analysis that appeared in the Nov. 11, 2000, British Medical Journal found long-term aspirin therapy to be associated with a risk of gastrointestinal hemorrhage in about one in 100 patients who are treated for 28 months. The authors also noted there was insufficient evidence to support the use of lower-dosage aspirin to reduce that risk. And the link between Reye's syndrome and aspirin, first discovered in the early 1980s, is also strong evidence of the dark side of aspirin. The Centers for Disease Control and Prevention first linked the use of aspirin among children with the flu or chickenpox to outbreaks of the rare, but serious neurologic disorder. The success of the campaign to educate parents on the dangers of treating children with aspirin has led to a dramatic decline in the number of cases of Reye's syndrome, according to the CDC. After a high of 555 cases in 1980, the number declined rapidly to fewer than 37 cases each year since 1987. Because aspirin is such a familiar presence in the medicine chest, there is also concern that people may not exercise necessary caution. They may think, "If one a day is good, then four a day is four times as good," said Dr. Bryant. And they might not discuss this with their physicians. Most people, though, can take aspirin safely. And it has three great advantages, according to Dr. Bryant: "It has been around a long time, so most adults know how they react to it; it is widely known how it works in general; and it is very cheap compared to other drugs." ADDITIONAL INFORMATION:Aspiring through the agesc. 400 B.C. Greek physician Hippocrates is thought to have prescribed chewing the white willow tree's bark and leaves for pain and fever relief.
WeblinkCoronary disease risk assessment tool from National Cholesterol Education Program Article from U.S. Preventive Services Task Force on aspirin for the primary prevention of cardiovascular events (http://www.ahrq.gov/clinic/3rduspstf/aspirin/asprr.htm) Aspirin Foundation of America (http://www.aspirin.org/) Self-assessment tool for cardiovascular risk (http://www.med-decisions.com/) Copyright 2002 American Medical Association. All rights reserved.
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