Amy Corderoy
September 14, 2010
One of Australia’s best-selling painkillers, Voltaren, should be banned, according to the co-author of a study linking the drug to a higher risk of stroke in healthy individuals who were not previously considered at risk.
Voltaren, which contains diclofenac, is part of a class of drugs known as non-steroidal anti-inflammatory drugs (NSAIDs), all of which were found to increase stroke risk, according to an extensive Danish study. Diclofenac was deemed as dangerous as Vioxx, a drug withdrawn from the Australian market in 2004 after being linked to an increased risk of heart attacks.
The study, which analysed data from Denmark’s entire population of 5.5 million people over eight years, found that more than 2.6 million people had a prescription for NSAIDs. Diclofenac, sold under 19 different brands in Australia, including Voltaren, was found to increase stroke risk by 86 per cent in those not previously thought to be at risk.
Ibuprofen, sold as Nurofen and Advil, was also linked to a 30 per cent increased risk of stroke when doses exceeded 1200 milligrams per day.
A spokesperson for Novartis Australia, the manufacturer of Voltaren, acknowledged the study but said the findings did not alter the benefit-to-risk assessment for diclofenac. She advised that diclofenac should be used at the lowest effective dose for the shortest possible time, as directed by a healthcare professional.
In the last financial year, nearly 656,000 prescriptions for higher-strength Voltaren and 246,000 prescriptions for high-dose ibuprofen were covered under the Pharmaceutical Benefits Scheme (PBS).
Gunnar Gislason, senior cardiologist at Gentofte University Hospital and co-author of the study, told the Herald that ibuprofen should be available by prescription only, and diclofenac should be banned. “The use of these drugs is so widespread, and we have been using them for quite a few years without considering their potential side effects,” he said. “It is important to inform the public that these drugs should be used carefully.”
Professor Ric Day, clinical pharmacologist at the University of NSW and St Vincent’s Hospital, said that while the study focused on healthy individuals, it was especially significant for those at risk of heart attack and stroke, such as people with diabetes or high blood pressure. “For older individuals with these conditions, the risks are significant,” he added, emphasizing that people should be properly informed about the potential dangers at high doses.
David Henry, head of the Institute for Clinical Evaluative Sciences in Canada and adjunct professor at the University of Newcastle, echoed the concerns, noting that diclofenac has consistently been shown to carry the same heart attack risk as Vioxx and should be taken off the market. “There is no good reason for diclofenac to remain available, but regulatory authorities have not addressed the issue,” he said.
Professor Henry also criticised Australia’s lack of data linking hospital records and prescribing information, saying, “It is a disgrace… Australia relies on overseas studies to assess drug safety. Why can’t Australia evaluate the safety of its own drugs?”
A spokesperson for the Therapeutic Goods Administration (TGA) confirmed receiving eight reports of heart attacks and one of angina in patients taking diclofenac, where a causal link was suspected. There were no such reports for patients taking ibuprofen.
