A painkiller prescribed more than 17m times by GPs last year can increase the risk of heart attack and stroke by 40%, according to new research. This type of painkiller, non-steroidal anti-inflammatories (NSAID), are also available over the counter and are used to relieve inflammatory pain such as backache, arthritis and gout. People also use these painkillers, which include Ibuprofen, to relieve headaches and colds. Doctors knew about the risks from NSAIDs, but may not have realised until now that some NSAIDs, for example diclofenac, were more risky than others.

The dilemma

NSAIDs work well, especially for arthritis. Paracetamol may take only the edge of inflammatory pain; aspirin, at sufficient doses, is more toxic to your stomach lining; taking codeine for more than three days has a risk of constipation and addiction.

The research in the journal PLoS Medicine analysed studies looking at the relationship between NSAIDs and strokes or heart attacks. Because of the numbers of people involved (more than 2.7 million) they were likely to pick up side-effects of these drugs (individual studies had made allowances for factors that might have biased the results, eg people smoking or having high blood pressure). The researchers found that taking the NSAID diclofenac at lower doses increased the risk of heart attack and stroke by 22%, but by 40% at higher prescription doses. The increase in risk started after a week for most of the NSAIDs, but immediately with diclofenac. Newer NSAIDs, (called Cox-2 selective NSAIDs) produced to reduce the risk of stomach ulcers, don't seem to have done the same for heart attacks or strokes. Celecoxib, a Cox-2 selective NSAID, caused an increase in risk at both low and high doses.

So should you ditch your favourite painkiller?

The solution

The paper's author, Dr Patricia McGettigan, says some NSAIDs are safer than others – Ibuprofen at a lower dose, for example. Naproxen, prescribed only half as often as diclofenac, was found not to be associated with increased risk. You also have to understand your background risk, says McGettigan. "If you have diabetes, if you have had a previous heart attack or stroke or have high blood pressure, then your risk could already be increased by 5-10% and if you are on a high dose of diclofenac it could go up by another 40%," she says. "If you are a young, fit person then your risk will be negligible."

"You need to ask yourself if this drug is really working for you," says McGettigan. "Are you using a lot of it and have you have tried other non-steroidal anti-inflammatory drugs? You need to talk to your doctor."