Daily aspirin therapy can be a lifesaving option, but it's not for everyone. Get the facts before considering a daily aspirin.

By Mayo Clinic Staff

Daily aspirin therapy may lower your risk of heart attack, but daily aspirin therapy isn't for everyone. Is it right for you?

If you've had a heart attack or stroke, your doctor will likely recommend you take a daily aspirin unless you have a serious allergy or history of bleeding. If you have a high risk of having a first heart attack, your doctor might recommend aspirin after weighing the risks and benefits.

You shouldn't start daily aspirin therapy on your own, however. While taking an occasional aspirin or two is safe for most adults to use for headaches, body aches or fever, daily use of aspirin can have serious side effects, including internal bleeding.

Aspirin interferes with your blood's clotting action. When you bleed, your blood's clotting cells, called platelets, build up at the site of your wound. The platelets help form a plug that seals the opening in your blood vessel to stop bleeding.

But this clotting can also happen within the vessels that supply your heart with blood. If your blood vessels are already narrowed from atherosclerosis — the buildup of fatty deposits in your arteries — a fatty deposit in your vessel lining can burst.

Then, a blood clot can quickly form and block the artery. This prevents blood flow to the heart and causes a heart attack. Aspirin therapy reduces the clumping action of platelets — possibly preventing a heart attack.

Talk with your doctor about whether daily aspirin therapy might help you prevent a heart attack. Your doctor may suggest daily aspirin therapy if:

  • You've already had a heart attack or stroke
  • You haven't had a heart attack, but you have had a stent placed in a coronary artery, you have had coronary bypass surgery, or you have chest pain due to coronary artery disease (angina)
  • You've never had a heart attack, but you're at high risk of having one
  • You have diabetes and at least one other heart disease risk factor — such as smoking or high blood pressure — and you're a man older than 50 or a woman older than 60

Although aspirin has been recommended in the past for certain groups of people without a history of heart attack, there's some disagreement among experts about whether the benefits of aspirin outweigh its potential risks. The Food and Drug Administration doesn't recommend aspirin therapy for the prevention of heart attacks in people who haven't already had a heart attack, stroke or another cardiovascular condition.

Guidelines are varied between organizations, but they're evolving as more research is done. The benefit of daily aspirin therapy doesn't outweigh the risk of bleeding in people with a low risk of heart attacks. The higher your risk of heart attack, the more likely it is that the benefits of daily aspirin outweigh the risk of bleeding.

In women, daily aspirin therapy may be more effective at preventing strokes than heart attacks. The bottom line is that before taking a daily aspirin you should have a discussion with your doctor.

Before starting daily aspirin therapy under the advice of your doctor, you should let him or her know if you have a health condition that could increase your risk of bleeding or other complications. These conditions include:

  • A bleeding or clotting disorder (bleeding easily)
  • Aspirin allergy, which can include asthma caused by aspirin
  • Bleeding stomach ulcers

Your doctor will discuss what dose is right for you. Very low doses of aspirin —75 milligrams (mg), which is less than a standard baby aspirin — can be effective. Your doctor will usually prescribe a daily dose anywhere from 81 mg — the amount in a baby aspirin — to 325 mg (a regular strength tablet). If you have had a heart attack or have had a heart stent placed, it's very important to take aspirin and any other blood-thinning medications exactly as recommended.

You might be surprised to learn that stopping daily aspirin therapy can have a rebound effect that may increase your risk of heart attack. If you have had a heart attack or a stent placed in one or more of your heart arteries, stopping daily aspirin therapy can lead to a life-threatening heart attack.

If you have been taking daily aspirin therapy and want to stop, it's important to talk to your doctor before making any changes. Suddenly stopping daily aspirin therapy could have a rebound effect that may trigger a blood clot.

Both aspirin and nonsteroidal anti-inflammatory medications (NSAIDs), such as ibuprofen (Motrin IB, Advil, others) and naproxen sodium (Aleve), reduce the clotting action of blood platelets. Regular use of nonsteroidal anti-inflammatory medications can increase your bleeding risk.

Some NSAIDs can increase the risk of heart attacks on their own. Additionally, some NSAIDs can adversely interact with aspirin, increasing the risk of bleeding even more.

If you need only a single dose of ibuprofen, take it two hours after the aspirin. If you need to take ibuprofen or other NSAIDs more often, talk to your doctor about medication alternatives that won't interfere with daily aspirin therapy.

Side effects and complications of taking aspirin include:

  • Stroke caused by a burst blood vessel. While daily aspirin can help prevent a clot-related stroke, it may increase your risk of a bleeding stroke (hemorrhagic stroke).
  • Gastrointestinal bleeding. Daily aspirin use increases your risk of developing a stomach ulcer. And, if you have a bleeding ulcer or bleeding anywhere else in your gastrointestinal tract, taking aspirin will cause it to bleed more, perhaps to a life-threatening extent.
  • Allergic reaction. If you're allergic to aspirin, taking any amount of aspirin can trigger a serious allergic reaction.

If you're taking aspirin and need a surgical procedure or dental work, be sure to tell the surgeon or dentist that you take daily aspirin and how much. Otherwise you risk excessive bleeding during surgery. Don't stop taking aspirin without talking to your doctor, however.

The Food and Drug Administration also warns that people who regularly take aspirin should limit the amount of alcohol they drink because of its additional blood-thinning effects and potential to upset your stomach. If you choose to drink alcohol, do so in moderation. For healthy adults, that means up to one drink a day for women of all ages and men older than age 65, and up to two drinks a day for men age 65 and younger.

If you're already taking an anticoagulant, such as warfarin (Coumadin, Jantoven), apixaban (Eliquis), dabigatran (Pradaxa) or rivaroxaban (Xarelto) for another condition, combining it with aspirin may greatly increase the risk of major bleeding complications. However, there may be some conditions for which combining a low dose of aspirin with warfarin or another anticoagulant is appropriate. But, this therapy always needs to be carefully discussed with your doctor.

Other medications and herbal supplements also may increase your risk of bleeding. Medications that can interact with aspirin include:

  • Heparin
  • Ibuprofen (Advil, Motrin IB, others), when taken regularly
  • Corticosteroids
  • Clopidogrel (Plavix)
  • Some antidepressants (clomipramine, paroxetine, others)

Taking some dietary supplements can also increase your bleeding risk. These include:

  • Bilberry
  • Capsaicin
  • Cat's claw
  • Danshen
  • Evening primrose oil
  • Ginkgo
  • Kava
  • Ma-Huang
  • Omega-3 fatty acids (fish oil)

If you think you're having a heart attack, the most important thing for you to do is call 911 or emergency medical services. Don't delay calling for help. Aspirin alone won't save your life if you're having a heart attack.

The operator may advise you to chew an aspirin, but will first ask questions to make sure you're not allergic to aspirin or have any other health conditions that would make taking an aspirin during a heart attack too risky. It's OK to chew an aspirin if your doctor has previously told you to do so if you think you're having a heart attack — but call 911 or emergency medical services first.

Enteric-coated aspirin is designed to pass through your stomach and not disintegrate until it reaches your small intestine. It may be gentler on the stomach and may be appropriate for some people who take a daily aspirin, especially in those with a history of gastritis or ulcers.

However, some researchers think there's no evidence that taking an enteric-coated aspirin decreases your chance of developing gastrointestinal bleeding. In addition, some research has found that coated aspirin may not be as effective as plain aspirin. Talk to your doctor if you're concerned about ways to decrease your bleeding risk.

March 21, 2015