Vioxx risk may have begun in 4 monthsMay 19, 2006 | AP
Unpublished data from the Merck & Co. study that led the drugmaker to halt sales of Vioxx appear to show that the painkiller raised the risk of heart attack and stroke within just a few months not after at least 18 months’ use, as Merck has argued.
The company disputed that yesterday, saying it is "not scientifically appropriate" to draw conclusions based on a key graph in a 108-page report.
The news, first reported by National Public Radio, comes after prominent doctors said last week that Merck misrepresented other data from the same study.
Merck officials said last week that data from a follow-up a year after patients stopped taking Vioxx showed the risk ended soon after patients stopped taking it and that those who later had such complications had no legitimate lawsuit. But several doctors said they think the data instead showed that the heart and stroke risks persisted for at least a year.
The newly public data show the increased cardiovascular risk likely begins as early as four to six months and then increases, said Dr. Steven Nissen, a Cleveland Clinic cardiologist who heads a huge international study of painkiller safety.
"It didn’t really make a lot of sense that nothing happened for 18 months and then all of a sudden you would see a hazard," Nissen said yesterday.
Other doctors concurred.
Because few heart attacks and strokes occurred, Nissen said scientists can’t definitively say the painkiller caused the excess complications in the Vioxx group compared with those in the placebo group, but most would interpret it that way.
"There’s no 18-month delay until you see harm," said Dr. Curt Furberg, professor of public health science at Wake Forest University School of Medicine in Winston-Salem, N.C.
"You’re probably at risk the rest of your life," he added.
The study, known by the acronym APPROVe, included 2,586 patients, with half taking Vioxx and half dummy pills for three years. When the company first published APPROVe data, in February 2005 in The New England Journal of Medicine, it only included complications within 14 days of stopping the drug, even if patients stopped early. A key graph showed higher risk after 18 months.