Aspirin belongs to a family of drugs called nonsteroidal anti-inflammatory drugs (NSAIDs). It often is used to treat arthritis in older adults. Aspirin also is prescribed as a preventive medicine for illnesses such as heart disease. The Food and Drug Administration (FDA) has approved the use of aspirin for patients who have had a previous heart attack or unstable chest pain (angina) to reduce the risk of death and nonfatal heart attacks; patients with chronic stable angina to reduce the risk...
Aspirin belongs to a family of drugs called nonsteroidal anti-inflammatory drugs (NSAIDs). It often is used to treat arthritis in older adults. Aspirin also is prescribed as a preventive medicine for illnesses such as heart disease. The Food and Drug Administration (FDA) has approved the use of aspirin for patients who have had a previous heart attack or unstable chest pain (angina) to reduce the risk of death and nonfatal heart attacks; patients with chronic stable angina to reduce the risk of heart attacks and sudden death; patients who have undergone revascularization procedures, such as the placement of a stent, for a preexisting condition; patients with a suspected acute heart attack to reduce vascular mortality; and patients who have had ischemic stroke or transient ischemia of the brain due to fibrin platelet emboli (clots) to reduce death and nonfatal stroke.
The use of aspirin in the aforementioned situations is known as secondary prevention because the patient already has a preexisting cardiovascular condition.
However, aspirin should not be used for the primary prevention of heart attacks in patients without preexisting heart disease for two reasons. First, there is no convincing evidence that aspirin offers any benefit in the primary prevention of heart attacks. Second, aspirin increases the risk of bleeding.
There are several forms of aspirin available: plain aspirin, enteric-coated aspirin and buffered aspirin. In previous editions of Worst Pills, Best Pills News, we recommended the use of enteric-coated aspirin over plain or buffered aspirin because enteric coating was once thought to reduce the overall risk of bleeding in the gastrointestinal (GI) tract, as this form of aspirin does not dissolve in the stomach. The weight of the evidence now indicates that the risk of GI bleeding is similar among plain, enteric-coated and buffered aspirin.,,, This is probably at least partially due to the fact that once aspirin is absorbed into the blood it can cause GI bleeding not related to local irritation but due to its effects on diminishing the natural protection of the GI tract and blood clotting.
We have listed buffered aspirin (ASCRIPTIN, BUFFERIN) as a Do Not Use drug because it is no better than plain aspirin and is more costly.
NSAIDs can cause serious harm, including death, from bleeding in the stomach or intestines. Bleeding can occur at any time and without warning, and older people are more likely to experience adverse effects from bleeding. Combining aspirin with the antiplatelet drug clopidogrel (PLAVIX) further increases the risk of gastrointestinal bleeding. Aspirin use also increases the risk of bleeding between the skull and the outside of the brain (subdural hematoma), although the absolute increase in risk is very low.
Older adults are also more likely to have reduced liver and kidney function. Some doctors believe people over age 70 should be started on half the usual dose.
A 2013 study published in Circulation, the journal of the American Heart Association, found that patients with atrial fibrillation who were receiving oral anticoagulants (blood thinners for preventing blood clots) as well as aspirin had an increased risk of bleeding compared with patients who were receiving only oral anticoagulant therapy with no aspirin.
A study published in JAMA Internal Medicine in 2014 showed that the risk of major bleeding in patients with venous thromboembolism (VTE; blood clots in large veins which can break off and travel to the lung) using anticoagulants increased significantly when the patient also took NSAIDs or aspirin.
One meta-analysis (a study that combines data from many other studies) studied the risks and benefits of adding aspirin therapy to the drug regimen of patients who were already taking an oral anticoagulant such as warfarin (COUMADIN), including patients with atrial fibrillation or with mechanical heart valves. This study demonstrated that there is little support in the published literature for the common clinical practice of adding aspirin to oral anticoagulant therapy except in select patients with a mechanical heart valve. The additional risk of bleeding was not thought to be warranted.
Another study examined the effects of long-term, low-dose aspirin therapy in VTE in healthy women. The study found that aspirin therapy is not effective in primary prevention of VTE in women with low-to-moderate risk of VTE.
According to a study in the Annals of Internal Medicine, taking 75 to 81 milligrams of aspirin a day (one low-dose aspirin tablet) could be the safest, most effective way to prevent heart disease in patients who require aspirin therapy.
The study also found that taking doses of aspirin larger than 100 milligrams a day does not have any clear benefit for preventing heart disease — and it may actually be harmful to patients' health.
The Archives of Internal Medicine published a meta-analysis in 2012 in which the authors aimed to assess whether the benefits of aspirin for those without known cardiovascular disease would outweigh aspirin's increased risk of serious bleeding. The study found that aspirin, taken daily or every other day in low doses for primary prevention of cardiovascular death in patients without existing cardiovascular disease, was not effective in reducing cardiovascular death or death from cancer. Aspirin did, however, increase clinically important bleeding events.
Patients who frequently use medication to relieve headache pain may develop a condition known as medication overuse headache (MOH). According to a 2004 review published in the medical journal Lancet Neurology, there is substantial evidence that all headache drugs can cause MOH in patients who use these drugs excessively.
The March 2013 issue of Worst Pills, Best Pills News discussed two recent studies dealing with MOH. In the first study, the treatment for MOH was simple: basic information tailored to the individual patient, including a discussion with the patient's doctor of both the role of drugs in developing MOH and the likelihood that stopping painkiller overuse would lead to an improvement. The second study involved a review of MOH treatment guidelines, including evidence concerning the manner in which the previously overused painkillers were discontinued.
Based on the results of both studies, patients should discuss with their doctors the important details of MOH and, depending on their individual case, the type of withdrawal from the MOH-causing drugs that is best for them.
Results of a major government-funded clinical trial, called ASPREE, published in the New England Journal of Medicine (NEJM) in 2018 demonstrated that long-term daily use of low-dose aspirin in elderly adults who did not have cardiovascular disease, dementia or physical disability did not decrease the risk of heart attack, stroke or other serious cardiovascular disease. However, it did increase the risk of major bleeding.,,
Results of another major study, called ASCEND, also published in the NEJM in 2018, showed that daily aspirin use in diabetic patients who had never had cardiovascular disease led to a lower risk of serious heart disease, but this benefit was offset by an increased risk of major bleeding.
A third major study, called ARRIVE, published in Lancet in 2018, studied long-term daily use of low-dose aspirin in adults (average age 64 years) without prior cardiovascular disease or diabetes who had low 10-year risk of developing cardiovascular disease, although the researchers had aimed to enroll subjects with moderate risk. After a median of five years of follow-up, the two groups had similar rates of adverse cardiovascular events, but 1% of the aspirin-group subjects experienced gastrointestinal bleeding compared with only 0.5% of the placebo-group subjects, a difference that was statistically significant.
In 2021, New England Journal of Medicine published results of a new trial called ADAPTABLE that showed that in patients with a high risk of cardiovascular disease, daily low-dose aspirin was equally effective as higher-dose aspirin for preventing strokes, heart attacks and deaths from cardiovascular disease.
Regulatory actions surrounding aspirin
2003: Bayer, the manufacturer of Genuine Bayer Aspirin, petitioned the FDA to allow the use of aspirin to reduce the risk of a first heart attack in patients with a coronary heart disease risk of 10% or greater over 10 years. This is known as primary prevention.
On Dec. 8, 2003, the FDA's Cardio-Renal Drugs Advisory Committee met to evaluate the results of five published clinical trials,,,, submitted by Bayer to support their petition. The committee refused to recommend aspirin for primary prevention. The official concerns of the FDA were:
In only one of the five studies submitted by Bayer was there a reduction in fatal heart attacks. In this study there was a larger, though not statistically significant, increase in fatal sudden death, strokes or other fatal cardiovascular events.
The lack of efficacy [prevention of cardiovascular events, primarily a first heart attack] in the face of associated morbidity (i.e., bleeding) prevents the recommendation of use of aspirin for the primary prevention of cardiovascular morbidity and mortality.
2020: The FDA and Health Canada (an agency in Canada similar to the FDA) warned that use NSAIDs at about 20 weeks or later in pregnancy rarely causes serious kidney problems in an unborn baby., These kidney problems can lead to oligohydramnios, a condition in which there are low levels of amniotic fluid surrounding the baby. Amniotic fluid normally provides a protective cushion and plays an important role in the development of a baby's lungs, digestive system and muscles. Oligohydramnios in turn can lead to decreased range of motion in a baby's arms and legs and delayed lung maturation.