Safer alternatives exist to diclofenac, say researchers at the Barts and the London School of Medicine and Dentistry, who want it banned worldwide.
Diclofenac, like ibuprofen, is a non-steroidal anti-inflammatory drug or ‘NSAID’. It is often prescribed after surgery and to combat arthritic pain, when ibuprofen is not strong enough.
It can also be purchased over the counter at a pharmacy without a prescription, for example in the branded form of Voltarol Pain-eze tablets.
But two years ago the Barts researchers found that it was linked with a 40 per cent increased risk of heart attack and stroke.
That analysis crystallised the fears of many doctors, who have raised concerns about the drug for years.
Another study, also published in 2011, indicated diclofenac raised the risk of dying from heart attack or stroke four-fold.
Writing in the journal PLoS Medicine Dr Patricia McGettigan, who led the 2011 study, said drugs regulators needed to take action now.
She said: “The regulators need to look at medicine like this on the basis that the evidence that it causes harm has been known for years but its sale and prescription patterns in England are only slowly drifting down.
“If it is not going to change appropriately then the regulators need to act, particularly when there is a safer alternative available.”
About five million prescriptions are made for diclofenac every year, according to official data. Although many take it regularly, lots of people take it as a ‘one off’, meaning it is likely that well over a million take it every year. The risks are highest in those who take it regularly.
Dr McGettigan, who has trained as both a pharmacist and doctor, noted the increased risk from diclofenac was not much less that from another drug, which was withdrawn in 2004. Vioxx, an arthritis drug, was found to raise the chance of heart attack and stroke by 45 per cent.
Diclofenac still appears on the World Health Organisation’s list of “essential medicines” in 74 countries, according to Dr McGettigan and her colleague David Henry, chief executive of the Institute for Clinical Evaluative Sciences at the University of Toronto, who contributed to the study.
Professor Henry said: “Given the availability of safer alternatives, diclofenac should be de-listed from national essential medicines lists.”
Dr McGettigan added: “Diclofenac has no advantage in terms of gastrointestinal safety and it has a clear cardiovascular disadvantage,” she said.
“Because it’s been around for so long people have become familiar with it and almost don’t believe it could have a side effect like this.
“There are strong arguments to revoke its marketing authorisations globally.”
A spokesman for the UK drugs regulator, the Medicines and Healthcare Products Regulatory Agency (MHRA), said diclofenac was “an extremely important NSAID”.
He said: “For most patients the risks of side-effects are outweighed by the benefits these drugs bring in managing pain.”
He continued: “The MHRA has carefully reviewed the safety profile of diclofenac as new data becomes available. This has resulted in updates to information for healthcare professionals and patients, and numerous communications to ensure that any risk to patients is minimised.
“Our advice remains that these medicines should be used for the shortest time necessary and at the lowest dose possible to control symptoms.”
A European review, instigated by the MHRA, was currently taking place, he added.
Maureen Talbot, senior cardiac nurse at the British Heart Foundation, urged caution when prescribing NSAIDs but did not say diclofenac should be banned.
She said: “The risks associated with non-steroidal anti-inflammatory painkillers, which include diclofenac, have been known for some years and they should always be prescribed with caution.
“Anyone taking these painkillers should be made aware of both their risks, especially of cardiovascular disease and internal bleeding, and benefits in treating debilitating pain such as that caused by arthritis.
“If you are taking these powerful drugs and are worried, discuss your concerns with your GP or pharmacist who will be able to help you decide whether the benefits outweigh the risks.”