Experts say Vioxx poses risks long after patients stop taking it

According to a leading American cardiologist patients who have taken the drug Vioxx are still at high risk of heart attacks or strokes even after they stop taking the medication.

Dr. Steven Nissen has disputed Merck & Co's interpretation on the safety of patients once they stop taking Vioxx, saying they remain at high risk of heart attacks or strokes for some time afterwards.

Dr Nissen, interim chairman of cardiology of the department of cardiovascular medicine at The Cleveland Clinic, says drug manufacturer Merck has misrepresented the analysis of data from a follow-up review of patients involved in the trial that ultimately led to the medication being withdrawn from the market.

Nissen says it is important that people are informed because patients who have taken the drug will need increased surveillance by their physicians and increased awareness of their risks in the year subsequent to stopping the drug; Nissen believes that risk may extend beyond a year.

New "preliminary" data from the Merck-sponsored 'APPROVe' study released by the company indicates that in the first three years of the study patients had a 92% higher risk of stroke and heart attack than those taking an inactive placebo pill.

A year after stopping Vioxx, the 1,721 patients still had a 74% higher stroke/heart attack risk.

During that year, 28 patients who had taken Vioxx and 16 patients who had taken placebo pills had a stroke or heart attack.

Merck says the difference has no statistical significance and dismiss the finding as simply chance denying any scientifically proven risk to people who stop taking Vioxx.

However the continued safety of the many people who took the heavily promoted drug before its risks became known are at stake.

Vioxx was withdrawn from the market in September 2004 following a three-year study which found that it doubled the risk of heart attack and strokes in patients taking it for at least 18 months.

Nissen says the relatively small total number of adverse heart events in the follow-up year, allowed Merck to claim no statistical significant difference even though the actual numbers tell a different story.

He says it is clear that the hazard stays constant even after the drug is stopped and the new data indicates that Vioxx may cause permanent damage.

Dr. Nissens views are supported by other experts in the field.

Merck says it stands by it's statement and say they are attempting to be as transparent as possible.

The company is facing more than 11,500 lawsuits from people who claim to have been harmed directly and indirectly by Vioxx.