Diclofenac - an anti-inflammatory that is in scores of prescription and over-the-counter preparations such as Cataflam and Voltaren - raises the risk of serious heart problems and stroke by 40 per cent. This is just 5 per cent below the risk associated with Vioxx, another painkiller commonly given for arthritis.
The drug was the most commonly prescribed NSAID (non-steroidal, anti-inflammatory drug) in the UK last year with nearly 6 million prescriptions written out, and just as many of the drugs were sold over-the-counter in pharmacies.
This heart risk, discovered by researchers from Hull York Medical School, means that the drug could be responsible for many thousands of deaths every year, possibly close to the levels caused by Vioxx.
A new NSAID, Arcoxia (etoricoxib), has a similar heart risk as Vioxx, the researchers also found.
(Source: PLoS Medicine, 2011; 8: e1001098).