Wednesday, September 13, 2006

Merck Challenged about validity of Vioxx Clinical Trials

Two studies offer more evidence about the dangers of some painkillers, adding kidney problems to heart concerns already raised with the drug once sold as Vioxx, researchers said.

One report from Boston's Brigham and Women's Hospital and Harvard Medical School said an analysis of 114 studies involving more than 116,000 people showed that rofecoxib (the chemical name for Vioxx) "was associated with increased renal and (heart) arrhythmia risks."

Why the drug would cause kidney damage is unclear, it added.

Merck & Co Inc. withdrew Vioxx from the market in September 2004 after a three-year study showed it doubled the risk of heart attack and strokes in patients taking it for at least 18 months.

A second report from the University of Newcastle, New South Wales, Australia, said a look at 23 studies confirms findings of an increased risk of heart problems with Vioxx that could be found "during the first 30 days of treatment. This conclusion is consistent with a recent reanalysis ... which contradicts the original suggestion that the vascular risk was only seen after 18 months."

Merck is facing more than 11,500 product liability lawsuits from people claiming to have been harmed by Vioxx.

"Those studies will also be used to cross-examine and impeach Merck's experts who testify that there is no link between the drug and the injuries," McClellan said. "The impact could be profound in the outcomes of the trials."

Merck said 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 -- sold as Celebrex by Pfizer Inc. -- was not associated with heart problems at a dose no greater than 200 milligrams a day.

In his editorial, Graham said the studies demonstrate that Vioxx "increases the risk of acute myocardial infarction at low and high doses" and that "there is no initial 18-month period of immunity from risk."

He said Celebrex increases heart risk at doses higher than 200 milligrams per day and several other non-steroidal anti-inflammatory drugs (NSAIDs) increase risk, including diclofenac, meloxicam, indomethacin and "probably" ibuprofen, while studies agree 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 sold as Aleve by Bayer Corp..

I read the JAMA science article, the data is quite clear to me.


Merck closed today at $41.09, down 2.5% on NYSE trading.

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