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Aspirin has earned its fame as a pain relief wonder drug. It eases headaches, lowers fevers, and reduces swelling. What's more, studies show that daily doses as low as 81 milligrams -- the amount in a baby aspirin -- can reduce the odds of heart attacks and strokes in people who are at risk. About 25 million Americans take aspirin for heart diseaseheart disease protection every day.
But there's a catch. Like any other drug, aspirin has dangers. When taken regularly, it can cause bleeding of the stomach and intestine -- especially in sensitive people. It can also interact with over-the-counter painkillers, causing unwanted side effects. Yet many people don't know this. Some take aspirin as casually as they pop a daily multivitamin.
"People have this skewed impression that over-the-counter medicines are harmless," says Curtis Barr, PharmD, associate professor of pharmacy practice at the Creighton University School of Pharmacy and Health Professions in Omaha, Neb.
That goes double for daily aspirin. "People think, 'It's just baby aspirin after all,'" says Byron Cryer, MD, a spokesman for the American Gastroenterological Association. "'So how bad could it be?'"
Yet it's a potent drug, and every year low-dose aspirin helps send tens of thousands to the hospital with bleeding.
So you must never start daily aspirin without your doctor's OK. If you have been prescribed daily aspirin, you need to know your risks -- before you next reach for a bottle of pain reliever.
Aspirin: The Pros and Cons
While aspirin may be best known as a painkiller, it also works as a blood thinner. Heart attacks and most strokes are caused by blood clots in the heart or brain. Aspirin decreases the blood's natural tendency to clot, allowing it to flow more easily -- reducing the risks of these complications.
But there's the problem. For the same reason that aspirin helps prevent strokes and heart attacks -- reducing the blood's tendency to clot -- it also raises the risk of bleeding elsewhere in the body. Bleeding that can be caused by the reduced ability of blood to clot.
Aspirin also has a special impact on the gastrointestinal tract. It blocks the effects of certain hormone-like substances called prostaglandins. These chemicals protect the stomach and gastrointestinal tract from damage. Aspirin can strip away this protection. Natural acids and enzymes in the stomach, which help digest food, can then injure the lining of the gastrointestinal tract. This can result in ulcersulcers and bleeding. Whether the aspirin is buffered or coated makes no difference. And because aspirin also prevents clotting, the bleeding is worse than normal.
Unfortunately, even low doses of aspirin have this effect, says Cryer, who is also an associate professor of medicine at the University of Texas Southwestern Medical School in Dallas. He worked on a study that tried to find a dose of aspirin that was low enough to avoid these side effects.
"We found that even just 10 milligrams -- which is too low to have any cardiovascular benefit -- posed the same risk of gastrointestinal damage as doses that were over 30 times higher," Cryer tells WebMD.
Compounding Aspirin's Risks
Aspirin is in a class of medicines called nonsteroidal anti-inflammatory drugs (NSAIDs.) This includes pain relievers like:
While other NSAIDs do not have aspirin's cardiovascular benefits, they share the same risks. Aspirin and other NSAIDs can:
Raise the risk of certain strokes. While most strokes are caused by clots, some are caused by bleeding in the brain. Thinning the blood increases this risk.
Raise the risk of damage to the kidneys and liver. In general, kidney or liver damage is only a risk when using high doses of NSAIDs regularly. But people who already have kidney or liver disease should talk to their doctors before using them.
Trigger allergic reactions. Many people are allergic to NSAIDS. People with asthmaasthma are especially at risk.
But the most common risk from NSAIDs is damage to the gastrointestinal tract. According to the American Gastroenterological Association, 103,000 people are hospitalized every year because of these side effects; 16,500 people die. And of all the people who are diagnosed with GI bleeding from an NSAID, a whopping 40% are taking low-dose aspirin, says Cryer.
What's worse, if you take aspirin and another NSAID regularly, you greatly increase the risk.
"Taking two NSAIDs -- like baby aspirin for heart protection and ibuprofen for pain relief -- increases your risk of gastrointestinal bleeding by nine times," says Cryer.
Safe Pain Relief When You're on Aspirin Therapy
So if you do take daily aspirin, what are your options the next time you pull a muscle or get a headache? Luckily, you don't have to grin and bear it.
One over-the-counter option is acetaminophen, which is sold as Panadol and Tylenol. It is not an NSAID: it works differently and has different risks.
For more severe pain, Cryer says that you could turn to prescription narcotics. These include drugs like OxyContin, Percocet, and Vicodin.
However, these drugs have drawbacks as well. First of all, none of them will help with swelling. High doses of acetaminophen regularly can cause serious liver damage. Narcotics taken regularly have other side effects, including constipationconstipation and a risk of addiction.
But what if you have arthritisarthritis and a risk of heart attackheart attack? What if you need both a daily aspirin and an NSAID for pain and swelling?
Then there's another option, says Cryer. You could also take a proton pump inhibitor. These drugs -- like prescription Aciphex, Nexium, Prevacid, Prilosec, and Protonix and the over-the-counter Prilosec OTC -- reduce the amount of acid in your stomach. This lowers the risk of ulcersulcers or bleeding, even if you are taking aspirin and another NSAID.
Aspirin Therapy: Working With Your Doctor
Cryer and Barr both say that we should not lose sight of aspirin's benefits.
"Having said all of these negative things about aspirin," says Cryer, "I want to stress that it's an excellent medicine for the right people. Everyone just needs to recognize that there are risks as well as benefits."
"Despite the risks, I think that more people should probably be on daily aspirin therapy," says Barr. "Many people at risk of cardiovascular disease -- men over 40, postmenopausal women, people with high blood pressure, high cholesterol or especially diabetes -- should be getting low-dose aspirin, but aren't."
If you take daily aspirin -- or are considering it -- here are some tips.
Make sure your doctor (or doctors) knows about all other medicines you take. This is key if you see multiple specialists, says Barr. For instance, a rheumatologist might prescribe an NSAID for your arthritis, but your cardiologist might suggest low-dose aspirin. Each doctor needs to know what the other is doing. Otherwise, you could get into trouble.
Watch out for NSAIDs in other products. NSAIDs, including aspirin, are common ingredients. They can pop up in places you might not expect, says Barr. For instance, some cold and flu remedies, sleep aids, and even antacids contain aspirin and other NSAIDs.
Watch out for signs of gastrointestinal bleeding. Signs include vomiting blood or dark stools. Unfortunately, these are often the first symptoms that something is wrong, says Cryer. Sometimes, stomach upset or pain can be an early warning.
Never start taking daily aspirin without your doctor's approval. It could do you more harm than good.
Cryer hopes that, in the future, some of aspirin's risks will be reduced.
"What we really need is a safer version of aspirin," he tells WebMD. "That's what the pharmaceutical companies are working on now." But Cryer says that this hypothetical safer aspirin is a ways off -- if it's coming at all.
For now, he says, we have to make do with the imperfect wonder drug we've got.
Published July 12, 2006.
SOURCES: American Academy of Allergy, Asthma and Immunology web site, "Aspirin/NSAID Sensitivity." American Gastroenterological Association web site, "Common Pain Relievers Can Cause Serious Problems." American Heart Association web site, "Aspirin in Heart Attack and Stroke Prevention." Curtis Barr, PharmD, associate professor of pharmacy practice, Creighton University School of Pharmacy and Health Professions, Omaha, Neb. Byron Cryer, MD, spokesman, American Gastroenterological Association; associate professor of Medicine, University of Texas Southwestern Medical School, Dallas. Cryer, B. The American Journal of Managed Care, December 2002; vol 8: pp S701-08. International Foundation for Functional Gastrointestinal Disorders AboutGERD web site: "NSAIDs: Good for the Joints, Bad for the Gut?" U.S. Preventive Services Task Force, "Aspirin for the Primary prevention of Cardiovascular Events: Recommendation and Rationale," Annals of Internal Medicine, January 2002; vol 136: pp 157-160.