Common painkillers used by millions of people around the UK have been linked to an increased risk of a heart attack, researchers have warned.

The study published in the British Medical Journal (BMJ), found that taking any dose of the non-steroidal anti-inflammatory drugs such as ibuprofen - known as Nsaids - for one week could increase the risk.

Researchers warned that doctors should consider "risks and benefits" before prescribing the drugs, particularly at higher doses.

An international team of scientists analysed data from almost 450,000 people for the study.

The researchers from Canada, Finland and Germany found that there was "a rapid onset of risk" for a heart attack within the first week of taking Nsaids.

The study also found that using the drugs for longer than one month did not increase the risk more than with shorter use.

Overall, the increased risk of suffering a heart attack was between 24% and 58% if taking celecoxib, ibuprofen, diclofenac, naproxen and rofecoxib, compared with not using these medications.

Dr Mike Knapton, an associate medical director at the British Heart Foundation, said the study "worryingly highlights just how quickly you become at risk of having a heart attack after starting Nsaids.

"Whether you are being prescribed painkillers like ibuprofen, or buying them over the counter, people must be made aware of the risk and alternative medication should be considered where appropriate," he said.

However John Smith, chief executive of the Proprietary Association of Great Britain said the Nsaids available to buy over the counter "are much lower doses than those prescribed".

"Prescribed Nsaids are also typically used daily and for much longer duration, often to treat long-term conditions.

"People taking over-the-counter Nsaids should not be concerned by this research if they are taking the medicine occasionally for short periods and according to the on-pack instructions," he added.

NSAIDS are non-selective non-steroidal anti-inflammatory drugs.

They are used to control both pain and inflammation and are commonly taken by people with arthritis.

Previous studies have linked the drugs to irregular heart rhythm, which increases the risk of heart attacks and strokes if taken regularly.

More than 14.5 million prescription items were dispensed in England for NSAIDs last year, according to NHS figures.