Vioxx® Heart Risks May Be Greater Than First Reported, Studies Suggest
TRENTON, NJ -- May 26, 2006 -- Vioxx® users may be at increased risk for heart attacks and strokes even if they took the drug for only a few months, according to recently reported data. The arthritis drug may also have longer lasting side effects than researchers previously reported.
Merck, the manufacturer of Vioxx®, has insisted that if Vioxx® increases the risk of heart attacks and strokes, it does so only in patients who use the drug for at least 18 months. It pulled Vioxx® from the market in September 2004 based on a three-year clinical trial in which the medication was used to treat patients with colon polyps (the APPROVe report). That study found that Vioxx® users had an increased risk of heart attacks and strokes compared with those who took placebos (sugar pills). Merck had pointed to figures from the APPROVe study to indicate that a patient must take Vioxx® for 18 months before heart problems can occur.
This month, Merck provided the results of a one-year follow-up of APPROVe participants. Its 107-page report to the Food and Drug Administration (FDA) includes a graph that indicates heart problems beginning at three or four months after Vioxx® use (Wall Street Journal, May 18, 2006). The original report had followed patients for only two weeks after they took Vioxx®.
"I had previously pointed out in publications that the [Vioxx®] risk is manifested quite early," commented Dr. Eric Topol, chairman of the cardiovascular medicine department at Case Western Reserve University in Cleveland and a frequent critic of Merck and Vioxx® (Forbes, HealthDay News, May 18, 2006). "There has never been anything to substantiate an 18-month incubation phase," he said.
A recent report from McGill University in Montreal, Canada, confirms the dangers of short-term Vioxx® use (CMAJ, May 23, 2006; 174(11)). The study looked at the government health records of 113,927 people aged 66 and older treated with Vioxx®, Celebrex® or no painkillers. The heart attack rate for Vioxx® users was greater than the rate for those taking no painkillers. A slightly increased heart attack rate among Celebrex® users was not statistically significant, although the increased rate among Vioxx® users was. About 25% of the elderly Vioxx® users who had heart attacks, had the heart attacks within the first two weeks of taking the drug.
Patients May Be At Risk Up to A Year After Discontinuing Vioxx®
Merck's latest report to the FDA also suggests that patients risk suffering a heart attack or stroke as much as a year after discontinuing Vioxx® use. The follow-up data showed that twenty-eight Vioxx® users had heart attacks and strokes one year after they stopped taking Vioxx®, but only 16 patients taking placebos suffered these conditions (Reuters, May 22, 2006). Vioxx® "could be causing permanent damage," suggested Dr. Curt Furberg, a professor of public health at Wake Forest University, and a member of the FDA Safety and Risk Management Advisory Committee (Reuters, May 19, 2006).
Merck has challenged the interpretations of various health experts, still claiming that short-term use of Vioxx® does not increase heart attack and stroke risk, and that any risk disappears after Vioxx® use ends.