July 10, 2001 (Washington) -- A woman who developed kidney failure after taking the popular arthritis drug Vioxx has raised more questions about the safety of this and similar drugs.
Vioxx belongs to a class of drugs known as COX-2 inhibitors. When they first emerged in the late 1990's, COX-2 inhibitors were touted as being safer and more effective than readily available nonsteroidal anti-inflammatory drugs, or NSAIDs, such as aspirin and ibuprofen.
But in recent months, the cardiovascular safety of Vioxx and Celebrex, another COX-2 inhibitor, has been questioned; and a report published in a recent issue of The Lancet suggests this group of drugs also can harm the kidneys.
In a June issue of the medical journal, Jose L. Roche, MD, and Jorge Fernandez-Alonso, MD, of the Hospital Universitario Virgen del Rocio in Spain, describe the case of a 67-year-old woman who developed a type of kidney failure. The condition seems to have been due to Vioxx because once the woman stopped taking the drug, she recovered.
Though it is known that NSAIDs can cause kidney failure, this case is the first to show that COX-2 inhibitors may be associated with the condition, Roche and Fernandez-Alonso report in The Lancet.
At the same time, both Merck, the manufacturer of Vioxx, has received reports of several cases of possible kidney failure associated with their drug, and Pharmacia, the manufacturer of Celebrex, has received 11 similar reports in people taking their drug. However, none of the reported conditions were conclusively diagnosed as kidney failure.
The suggested association between kidney failure and COX-2 inhibitors is not surprising, Larry Sasich, PharmD, MPH, of the consumer advocacy organization Public Citizen, tells WebMD. Kidney problems "are a side effect of all NSAIDs," including COX-2 inhibitors, he says.
He notes that the current labels for Celebrex and Vioxx carry the same warnings and risks as other NSAIDs, including the potential kidney damage.
Vioxx and Celebrex "are no more effective than other NSAIDs, and there appears to be no safety advantage," Sasich says. Arthritis patients would be better off financially and medically taking a cheaper NSAID, such as ibuprofen, which are a fraction of the price of the COX-2 inhibitors, Sasich adds.
Kidney failure is not the only concern, though. In February, the FDA and its arthritis drugs advisory committee reviewed whether COX-2 inhibitors increased the risk of heart attacks. That question was raised following a study Merck presented to support its contention that Vioxx is safer on the gastrointestinal tract than other NSAIDs.
The study found that Vioxx cut the occurrence of ulcers and other gastrointestinal problems by half compared with the over-the-counter NSAID Aleve. But the study also showed that people taking Vioxx had four times the risk of a heart attack.
So, should people taking Vioxx also take aspirin to reduce their risk of a heart attack? Not an easy question to answer since aspirin can increase the risk of gastrointestinal problems.
However, Merck has reviewed all their Vioxx studies and found no evidence that the drug increases the risk of a heart attack compared with other NSAIDs, company spokeswoman Christine Fanelle tells WebMD. The company contends that Vioxx's effect on the heart is negligible and that it only appeared to increase the risk of a heart attack because Aleve, like aspirin, actually reduces heart attack risk.
But some patients at risk for a heart attack may already be taking aspirin to protect their hearts, and Merck has a trial underway now to determine if using Vioxx and aspirin together will increase the risk of gastrointestinal problems. The results should be out next year, Fanelle says.
Other data gave the FDA reason to be concerned about the potential for Celebrex to cause heart problems. A study published in the Journal of the American Medical Association last year found that Celebrex was associated with an increased risk of heart attack and other heart problems.
At a February FDA meeting, Steven Nissen, MD, a cardiologist at the Cleveland Clinic Foundation and an adviser to the FDA, said in reference to Celebrex, "The question is, are we giving these agents to patients at higher cardiovascular risk, and if we do so, will we see something that we wished we didn't see, and I don't know the answer to that."
Whether the FDA will change the label of Vioxx or Celebrex to highlight the potential for heart problems remains uncertain.
Neither the FDA nor Pharmacia returned phone calls from WebMD.
Back to top of document