PARIS — Widely used prescription and non-prescription painkillers are associated with an increased risk of hospital admission for heart failure, according to a study released on Thursday.

The drugs in question are so-called NSAIDs, or non-steroidal anti-inflammatory drugs, including several known as COX-2 inhibitors.

Many are among the most commonly used drugs to alleviate pain and inflammation, and some were introduced over a century ago with minimal safety checks.

The broad link between the use of NSAIDs and heart failure is well established, but which drugs pose the greatest risk, and at what doses, remains poorly understood.

To get a clearer picture, a team of researchers led by Giovanni Corrao at the University of Milano-Bicocca combed through the medical records of nearly 10 million NSAID users in four European countries: Germany, Britain, the Netherlands and Italy.

They identified 92,163 hospital admissions for heart failure and then checked to see which of 27 drugs -- and at what doses -- each of them was taking.

Overall, they found that current use of NSAID slightly raised the risk of hospital admission compared to past use for nine drugs.

These included diclofenac, ibuprofen, indomethacin, ketorolac, naproxen, nimesulide, and piroxicam, along with two COX 2 inhibitors, etoricoxib and rofecoxib.

At very high doses, some doubled the risk of hospital admission.

The researchers emphasised that the study was observational, meaning that it did not benefit from the controlled conditions of an experiment and thus could not draw firm conclusions about cause and effect.

But the findings "offer further evidence that the most frequently used individual NSAIDs and selective COX2 inhibitors are associated with an increased risk of hospital admissions," they concluded.

The study was published in BMJ, a leading medical journal.

"Even a small increase in cardiovascular risk is a concern for public health," two Danish heart experts, Gunnar Gislason and Christian Torp-Pedersen wrote in a comment, also in BMJ.

For one drug in particular -- diclofenac -- the European Society of Cardiology has recommended against its use at any dose, they noted.

Helen Williams, a consultant pharmacist for cardiovascular disease at the Royal Pharmaceutical Society in Britain, noted that the country’s National Health Service had been "moving away" from the powerful NSAIDs in recent years.

"Reassuringly," she added, "use of the most commonly purchased NSAID -- ibuprofen -- was associated with a lower overall increased risk" compared to the other medicines, she added in a comment released by the Science Media Centre. — AFP