New research by Wellpoint Inc, the leading US private health insurance group, has confirmed a higher risk of heart attacks with the use of painkillers such as Vioxx, Bextra and Celebrex.
In a letter to the Food and Drug Administration (FDA), Wellpoint director Samuel Nussbaum on Wednesday said the results of the research showed the risks of heart attacks were 53% higher than normal for Bextra, 23% for Vioxx and 19% for Celebrex.
By comparison, the study found no increase in heart attacks or other heart-related diseases with traditional anti-inflammatory drugs.
The research compared Wellpoint prescription records between January 2001 and June 2004 of some 630,000 patients, aged 40 and over, who did not take the drugs to a group of 7,200 who did take the COX-2 inhibitors.
"Our findings ... without adjusting for risk factors and other confounding conditions, indicate that the COX-2 class of drugs increases the risk of myocardial infarction or stroke," Nussbaum said in his letter.
Vioxx was withdrawn from the market in September by pharmaceutical giant Merck after studies linked long-term use of the drug to cardiovascular risks.
"Our findings ... without adjusting for risk factors and other confounding conditions, indicate that the COX-2 class of drugs increases the risk of myocardial infarction or stroke"
Celebrex and Bextra, both made by Pfizer, are the only COX-2 type drugs still on the US market.
Pfizer and Merck said they had yet to analyse the Wellpoint research.
Wellpoint's study, the third to examine the risks of COX-2 inhibitors, was released on Wednesday, just as the FDA began three days of public hearings to determine if Bextra and Celebrex should also be withdrawn from the market.
An FDA-appointed committee of independent experts will hear from physicians, pharmaceutical companies, consumer groups and heart attack victims and their relatives before they issue recommendations that will lead to an FDA decision a few weeks later.