BBC News Online: Health

Painkiller 'blocks' aspirin benefits

Aspirin is often prescribed to thin the blood

The results of the study could have consequences for millions of people who take a small dose of aspirin every day to thin the blood, but who also take ibuprofen to treat conditions such as arthritis.

A team from the University of Pennsylvania School of Medicine found that ibuprofen set up a chemical blockade that prevented aspirin from thinning the blood.

When taken together, however, aspirin lost its effectiveness.

The report's co-author Garret Fitzgerald said: "Multiple daily doses of ibuprofen can undermine the cardioprotective effects of a daily aspirin regimen."

Medical alternatives

"Patients taking aspirin to protect against heart attack should seek the advice of their doctors before commencing additional treatments for pain and inflammation."

The British Heart Foundation said patients who want to take painkillers alongside aspirin should look at alternatives.

A British Heart Foundation spokeswoman said: "The preventative effects of aspirin are well established in reducing the risk of cardiovascular disease.

"It is therefore important that other drugs such as ibuprofen do not diminish the therapeutic effects of aspirin.

"Although this is an interesting study, the results should not deter the many thousands of people from taking their aspirin daily.

"There are alternatives to ibuprofen and patients who need to take a nonsteroidal anti-inflammatory drug as well as aspirin should seek advice from their GP about an alternative drug."