Vioxx study's correction links drug to earlier riskJun 27, 2006 | AP
A correction published Monday by a medical journal to a key study on withdrawn painkiller Vioxx reveals the risk of heart problems was elevated throughout the time people took the drug and did not develop only after 18 months of use as the drug's maker, Merck & Co., has contended.
The correction in the New England Journal of Medicine supports many doctors' contention that risks showed up with as little as four months of use.
Heart attacks and strokes occurred more frequently after people had been on the drug for at least 18 months, but the actual harm might have occurred much earlier, said Dr. Jeffrey Drazen, editor-in-chief of the journal, who worked with the authors to correct their original findings of the APPROVe trial, published in March 2005.
"It's a subtle but very critical point," Drazen said, comparing the situation to health problems being detected months after exposure to excessive radiation.
Cleveland Clinic cardiologist Dr. Steven Nissen, who has challenged the study's conclusions in the past and did so again in a separate letter also published by the medical journal on Monday, agreed.
"A key legal defense in the liability cases has been the suggestion that there was no risk until patients had taken the drug for 18 months," he said. Now, with the correction, "the authors have removed any claim that there was a delay in risk."
The main authors, Dr. Robert Bresalier of the University of Texas' M.D. Anderson Cancer Center and Dr. John A. Baron of Dartmouth Medical School, could not be reached for comment but acknowledge in a letter released by the journal that their statistical analysis had been flawed.
Merck, which paid for the study and helped conduct it, acknowledged the flawed analysis last month but claimed it did not change the results.
On Monday, Whitehouse Station-based Merck posted on its Web site what it called "an open letter to the scientific community," saying it stands behind the original results of the study.