New study re-evaluates cardiovascular risks of anti-inflammatory drugs
2 June 2006
New research has shown that high doses of some commonly used painkillers could increase the risk of heart attacks. The study based on the results of 138 randomised trials involving 140,000 patients found that some so-called Non-steroidal Anti-Inflammatory Drugs (NSAIDs), like ibuprofen and diclofenac, when taken in relatively high doses, increase the risk of heart attacks as much as COX-2 inhibitors such as Vioxx®. Vioxx® was withdrawn in 2004 after it was shown to increase the risk of heart disease.
The study was carried out by researchers at the Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU) at the University of Oxford and the Department of Pharmacology, University of Rome “La Sapienza”. The research team examined the results of all trials in which the cardiovascular effects of selective COX-2 inhibitors (also known as “coxibs”) and NSAIDs had been studied. By combining these results, they were able to estimate the effects of these drugs more reliably than in any of the individual trials, which were too small to study this question.
Dr Patricia Kearney, who coordinated the study, said: “The research showed that high dose regimens of ibuprofen and diclofenac increased the risk of heart attacks by as much as the coxibs, but the cardiovascular effects of another NSAID regimen, high-dose naproxen, appeared smaller.”
But the researchers stressed that although coxibs and some NSAIDs increase the risk of vascular events, the extra risk for the people studied in the trials, most of whom did not have vascular disease already, was modest and was equivalent to about 3 extra heart attacks per 1000 people taking the drug each year.
Dr Colin Baigent (UK Medical Research Council), who directed the research, said: “Many patients with severe chronic arthritis depend on these drugs to stay physically active, so it is important that they and their doctors can weigh up their benefits and potential harm. This research summarises what is known about cardiovascular risks, but doctors also need to consider the gastrointestinal and other potential risks of these drugs before deciding which is best for a particular patient.”
The researchers concluded that more randomised trials of NSAIDs and coxibs are needed to help in such decisions, but even if they are done, the results of these trials will not be available for some years. Professor Carlo Patrono (Professor of Pharmacology at the University of Rome “La Sapienza”), who jointly directed the work, said: “The best advice at present is that patients requiring an anti-inflammatory drug take the lowest effective dose of a NSAID or coxib for the shortest time necessary to control symptoms.”
For further information, or to arrange an interview with Colin Baigent (UK), contact the MRC Press Office:
Phone number: 020 7637 6011
Email: press.office@headoffice.mrc.ac.uk
The Clinical Trial Service Unit's (CTSU) work chiefly involves studies of the causes and treatment of "chronic" diseases such as cancer, heart attack or stroke (which, collectively, account for most adult deaths worldwide), although it does also involve some studies of other major conditions in developed and developing countries. Large-scale randomised and observational evidence is needed to investigate appropriately reliably the causes, prevention and treatment of premature death and disability in developed and developing countries. The CTSU experience shows that such studies can be practicable and relatively inexpensive if sufficient attention is paid to the details of study design. Such large-scale research does require widespread collaboration, so although around 165 people currently work in the unit at Oxford (including those responsible for statistical and clinical direction, computing, laboratory work, and administrative support), hundreds of others work full- or part-time on CTSU studies outside Oxford.
The Medical Research Council (MRC) is funded by the UK tax-payer. Its business is medical research aimed at improving human health. The research it supports and the scientists it trains meet the needs of the health services, the pharmaceutical and other health-related industries and the academic world. The MRC has funded work which has led to some of the most significant discoveries and achievements in medicine in the UK.
