For elderly people aged 75 years and above, daily intake of aspirin in a long-term setting could be dangerous, potentially leading to internal bleeding or blood clotting, a new study revealed.

At least 40 percent of older people take aspirin every day to prevent stroke or heart attack, scientists say. Research has also shown that low doses of aspirin (75 milligrams per day) can decrease the risk of heart problems among people who have already had stroke or heart attack.

However, authors of the new report now say that the effects of aspirin intake among elderly people have not been properly studied. Most studies include younger people aged 65 years and below, but people who are currently taking blood thinners are much older.

Aspirin Side Effects

Led by Peter Rothwell, researchers from the University of Oxford examined data from the Oxford Vascular Study, which followed more than 3,100 patients who previously had heart attack or stroke and were given antiplatelet drugs. Half of the patients were 75 years old or older at the beginning of the study.

In a span of 10 years, study authors found that approximately 314 elderly patients were taken to the hospital because of internal bleeding.

The risk of bleeding, particularly disabling or deadly bleeding, grew with age.

At 65 years old and below, the rate of fatal bleeding was less than 0.5 percent annually. Meanwhile, the rate increased to 1.5 percent for elderly patients aged 75 years old and above. Lastly, at age 85 and older, the rate rose to almost 2.5 percent.

In the end, the risk of deadly or disabling bleeding over 10 years was 10 times higher for elderly people aged 75 and older compared to younger patients.

Professor Rothwell said the possibility that aspirin can increase the risk of bleeding among elderly patients has been known for some time. Now, the new study provides a clearer picture of the size and severity of the risk of bleeding, he said.

Prescribe Proton Pump Inhibitors

Study authors say there is a way to offset the negative side effects of aspirin: by prescribing proton pump inhibitors alongside the treatment.

In fact, they further conclude that for elderly patients, adding PPIs to coagulation treatments is likely to lessen the intensity of major upper gastrointestinal bleeding because of antiplatelet therapy. PPIs can decrease upper gastrointestinal bleeding by about 70 to 90 percent.

Rothwell explained that the study found the benefits of PPIs outweigh the risks and that for elderly, the risk of bleeding without PPIs can be high. He also said patients should consult their doctors first before suddenly stopping their aspirin intake.

"These new data should provide reassurance that the benefits of PPI use at older ages will outweigh the risks," added Rothwell.

Details of the study were published in the journal The Lancet.