Two recent studies have offered still more evidence of the dangers linked with certain painkillers including kidney problems in addition to the heart concerns that was already raised with the drug marketed as Vioxx.
One report from Brigham and Women's Hospital, and Harvard Medical School, Boston, said that an analysis of 114 studies that involved over 116,000 people showed that rofecoxib commonly known as Vioxx "was associated with increased renal and (heart) arrhythmia risks."
The reason as to why the drug would cause kidney damage is still unclear.
In September 2004 Merck & Co Inc. withdrew Vioxx from the market after a three-year study revealed that it doubled the risk of heart attack and strokes in patients taking it for at least 18 months.
Another report from the University of Newcastle, New South Wales, Australia, following a review of 23 studies confirms the findings of an increased risk of heart problems with Vioxx that could be found "during the first 30 days of treatment in contrast to the the original suggestion that the vascular risk was only seen after 18 months."
Merck, however, facing more than 11,500 product liability lawsuits from people with claims of problems from Vioxx, has said that it still believes the data confirm the increased heart risk begins only after the medicine had been taken for 18 months.
The Australian analysis also found that celecoxib commonly sold as Celebrex and marketed by Pfizer Inc. was not associated with heart problems at a dose no greater than 200 milligrams a day.
Its review has also raised serious questions about the safety of diclofenac, an older (analgesic) drug marketed more in Europe than the United States.
The report added, "In conclusion ... diclofenac seems to share this risk and, unlike celecoxib, it appears to be harmful at commonly used doses. We believe there are grounds for reviewing its regulatory status."
The research details have been published in this week's Journal of the American Medical Association.
David Graham, a physician who works for the U.S. Food and Drug Administration said, "What does this all mean? First, rofecoxib (Vioxx) increases the risk of acute myocardial infarction at low and high doses." There is no initial 18-month period of immunity from risk."
He added that Celebrex "also increases (heart) risk at doses higher than 200 mg/d ... several other NSAIDs (non-steroidal anti-inflammatory drugs) increase risk, including ... diclofenac and meloxicam ... indomethacin and probably ibuprofen," while studies agree that naproxen is "neutral" for heart attack risk.
Graham added that for most patients with arthritis or other conditions requiring chronic pain relief "naproxen appears to be the safest NSAID choice from a cardiovascular perspective." Naproxen is commonly known as Aleve and marketed by Bayer Corp.