The risks of taking anti-inflammatory drug Vioxx could have been detected nearly four years before the drug was pulled from the market, according to analysis of nearly 30 clinical trials.
The findings, published in the Archives of Internal Medicine on Monday, analyzed 30 Vioxx trials involving around 20,000 individuals and fund evidence of the drug's risks from as early as 2000.
The Merck-made drug was pulled in 2004 after it was linked with serious cardiovascular problems, including heart attacks.
Much of trial data used in the meta-study has only become available because of litigation against the firm.
The study's authors, including Joseph Ross of the Mount Sinai School of Medicine in New York, said the results showed the need for the open publication of clinical trials.
"Physicians and the public deserve to be in a position to make informed choices about risk and benefits (of pharmaceutical products)," the authors said.
Merck voluntarily withdrew Vioxx from sale in September 2004 after a company internal study in 2001 showed the drug doubled the risks of heart attack in patients who took it for 18 months or longer.
The company has since faced a slew of lawsuits and was forced to pay billions of dollars in damages.