Ever since an 18th century English clergyman discovered that eating willow bark was a good way to reduce fevers, people have depended on aspirin -- the drugstore descendant of that home remedy -- to relieve the temperatures and assorted pains that ail them.
But recent revelations that aspirin carries previously hidden powers against heart attacks, stroke and migraines and possibly colon cancer have caused many consumers to ask whether this seemingly innocent pill may rightly be called a wonder drug.
And even if it isn't, isn't it harmless enough to place on the kitchen counter right beside the daily vitamins?
To these questions, doctors are saying, "Hold on."
Although studies demonstrate rather clearly that aspirin is a powerful weapon against heart attack and stroke -- at least in men, the population on whom it has been widely tested -- specialists agreed yesterday that this week's announcement that it may prevent colon cancer deaths is intriguing but far from conclusive.
And although the little white pill is cheap, generally safe and effective against many ailments, doctors insisted yesterday that its potential to cause stomach ulcers, allergic reactions and even brain hemorrhages is a powerful reason to view aspirin with respect.
Anyone considering taking it daily should first consult a physician, they said.
Many doctors have insisted for years that it's a serious drug: often as effective against inflammation and headache as prescription drugs and just as fraught with complications.
"For years, we've been trying to convince patients that when we say, 'Take aspirin,' we're talking about a real drug," said Dr. Stephen J. Gottlieb, a cardiologist at the University of Maryland Medical Center. "Just because it's available without a prescription doesn't mean it's not a good drug."
A wonder drug?
"No," Dr. Gottlieb added. "It's a good drug. It's just a wonder because people can't believe it's a real drug."
Sales of aspirin grow at a pace of 1 percent to 2 percent a year, according to Eugene Melnitchenko, a health care analyst with Legg Mason Wood Walker Inc. This year, aspirin accounts for about 40 percent of the $2.5 million market for analgesics -- a class of pain-relieving drugs that also includes acetaminophen, which appears under such brand names as Tylenol.
However unwilling to turn cartwheels over recent reports about aspirin's benefits, doctors said they were indeed impressed with the string of remarkable studies charting aspirin's usefulness against a variety of serious illnesses.
The clearest cases for aspirin's potential to work wonders come from studies published over the last four years, that document its benefits in preventing heart attacks.
In 1983, 22,000 healthy male physicians volunteered for a long-term study of the effects of aspirin in preventing heart attacks: Half would take a buffered aspirin every other day, and half would take a placebo.
By 1988, aspirin had so clearly demonstrated its ability to prevent heart attacks that the study was stopped, three years ahead of schedule.
But even those studies have their limits.
Dr. Charles Hennekens, the Harvard Medical School professor who headed the study, said the most he can say is that people who have already suffered a heart attack should take an aspirin a day to prevent the very real possibility of recurrence. People with high cholesterol or family histories of heart disease may also, with the concurrence of their physician, benefit from aspirin.
They shouldn't, he cautioned, take aspirin and forget to exercise and eat a low-fat, high-fiber diet.
"Do we want healthy people to start widespread aspirin use?" Dr. Hennekens said. "The data is incomplete on men and nonexistent on women." For healthy people, he said, the risk of getting an ulcer or other unforeseen side effects may outweigh the possible benefit of preventing a heart attack. So until further studies are completed, wait.
Studies over the last decade have also demonstrated that aspirin can be an effective weapon against stroke. Dr. Thomas Price, director of the stroke center at the University of Maryland Medical Center, said three or four aspirin a day are commonly prescribed for people who have had small "transient" strokes.
And two years ago, a study demonstrated that people suffering from atrial fibrillation -- the abnormal heart rhythm that struck President Bush earlier this year -- can also reduce their stroke risk if they take aspirin. This year a Dutch study also suggested that an aspirin a day may be just as effective as the three-aspirin dose that's standard practice.
News that aspirin may be effective against stroke and heart attackreally came as no surprise to many cardiologists, who said that scientists have long known that aspirin prevents the collection of platelets -- particles that cause blood to clot. Blood clots have long been implicated as the culprits in both heart attacks and strokes.
But doctors reacted with both surprise and skepticism when scientists with the American Cancer Society reported in yesterday's New England Journal of Medicine that aspirin may also prevent deaths from colon cancer: a disease that kills 53,000 Americans each year.
The findings stemmed from a cancer prevention study of 662,000 adults who, in 1982, filled out questionnaires detailing their lifestyle, diet, overall health and the medication they take. 00 Doctors then followed the patients for six years to see if they could find any links between the patient's personal histories and the diseases that killed them.
Dr. Michael J. Thun of the Cancer Society said he was surprised to find that the people who took aspirin at least every other day reduced their chance of dying from colon cancer by 40 percent to 50 percent. But he cautioned that the results may be misleading: He tracked cancer deaths, not cases. And, he said, the pill may actually have caused tumors to bleed earlier, leading earlier detection and treatment.
Also, while a recent study at Boston University yielded similar results, another at the University of Southern California suggested just the opposite.
"There are too many questions to base a recommendation as to whether people should be taking aspirin for cancer," Dr. Thun said. "There are too many uncertainties. Because aspirin causes bleeding and stomach ulcers in some people, it takes a high degree of certainty before one wants to make a recommendation to the public."
Some doctors believe the answers many come from a controlled study of 40,000 nurses at the Harvard Medical School. In that study, the nurses will be randomized so they either receive aspirin or a placebo. Doctors will carefully track the women to see if they develop heart attack, stroke or cancers of the colon, breast or lung.
Besides providing the first clear evidence about aspirin's ability to prevent heart attacks in women, it should also clear up mysteries surrounding the drug's cancer-fighting potential.
If aspirin does, indeed, prove an effective weapon against colon cancer, there may be a clear reason why. Quite apart from the blood-thinning mechanism by which it fights heart disease and stroke, aspirin is also known to inhibit the formation of prostaglandins, chemicals that stimulate tumor growth.
Whether it's really capable of mounting an effective assault against colon tumors is another thing, Dr. Thun admitted.
"What's uncanny is that aspirin is available over the counter," he said. "It seems like we're forever learning new things about its effects."
How it works
Aspirin blocks production of a family of fatty acids called prostaglandins. Reducing prostaglandins reduces the pain and fever associated with colds and flu and also inflammation, helping make arthritis and bursitis victims more comfortable. The most recent revelation is that aspirin may help prevent deaths from colon cancer. But it's a serious drug -- doctors say check with a physician before taking on a regular basis -- and has other effects on the human body, as well.
Major discoveries
In the 1980s, research showed aspirin reduces risk of heart attacks and thrombotic (clot-caused) strokes. It cuts the stickiness of blood-clotting particles called platelets and therefore reduces the risk of blood clots in blood vessels of the heart and brain.
Other effects
Aspirin can cause irritation of stomach lining, which can lead--to ulcers in some people if taken in large doses.
* Overdose symptoms include ringing in the ears, vomiting, dehydration, lethargy, confusion, and loss of consciousness.
When not to take
Without a doctor's advice if you have a bleeding disorder or if you are taking other drugs to reduce blood clotting, if you have uncontrolled high blood pressure (which can lead to a hemorrhagic stroke), if you are facing surgery in the next couple of weeks, if you have ulcers. Also, if you have kidney or liver disease or gout, if you are pregnant.
Don't take without a doctor's recommendation if you are or might be allergic to it. Aspirin allergy is most likely to occur in people with asthma.
Aspirin should not be given to anyone younger than 18 because of an association with Reye's Syndrome, a potentially life-threatening disease.
If you can take aspirin, however, a generic is as good as a brand name. An enteric-coated aspirin is safer for your stomach.