EDWARDSVILLE, Ill., March 27 (AP) — Jurors in a state court sided with Merck & Company, the maker of Vioxx, on Tuesday over claims that its painkiller, once a blockbuster, was responsible for the death in 2003 of a 52-year-old woman.

A Madison County jury found that while Merck knew or should have known about the dangers of Vioxx, the company had adequately warned doctors and consumers about possible complications of the drug.

After deliberating for about six hours over two days, jurors ruled that the painkiller was not a “proximate cause” of the death of the woman, Patty Schwaller, who had taken Vioxx for about 20 months.

During the trial, which lasted a month, Merck’s lawyers insisted that Mrs. Schwaller, who was 5 feet 2 inches tall and weighed between 250 and 300 pounds, had several risk factors for heart disease, including obesity, diabetes, high blood pressure and a sedentary lifestyle.

The company argued that Mrs. Schwaller’s obesity and the other health issues better explain her collapse and sudden death.

The suit was filed by Mrs. Schwaller’s husband, Frank Schwaller, who claimed that Vioxx had contributed to his wife’s death and that Merck had failed to adequately warn consumers that the drug increased the risk of cardiovascular problems.

His lawyers pressed that his wife had no heart attacks, strokes or symptoms of congestive heart disease before her fatal collapse, fueling their belief that Vioxx contributed to her death.

One juror, Jennifer Fourcault of Granite City, said the lack of an autopsy on Mrs. Schwaller, who was cremated, hampered the search for the truth. But in the end, she said, jurors unanimously concluded that Mrs. Schwaller’s own cardiac risk factors caused her death.

The victory was Merck’s 10th in 15 cases that have been tried in the growing litigation over Vioxx, which was withdrawn from the market in 2004 after Merck’s research showed it increased the risk of heart attacks and strokes. The trial was conducted in a county known for favoring plaintiffs with large awards.

Andy Crouppen, one of the lawyers for Mr. Schwaller, said the verdict would be appealed.