NEW YORK (CNN/Money) - The plaintiff in the first of several thousand Vioxx lawsuits took the stand in a Texas court Thursday and said she is taking antidepressants to alleviate the sorrow from her husband's death.

"I put on my game face, but I am a shell," Carol Ernst told the jurors, according to her lawyer W. Mark Lanier.

Carol Ernst has sued Merck & Co. (down $0.43 to $30.39, Research) for the 2001 death of her husband, Robert. Ernst's husband was taking Vioxx, an arthritis painkiller, and she blames the Merck drug for his death.

Ernst testified in state Supreme Court in Angleton, Texas, that she takes the antidepressants Prozac and Zoloft to help deal with her grief, according to Lanier.

But while a Merck lawyer said he "sympathizes" with Ernst, he insisted that Vioxx did not cause her husband's death.

"Merck feels great sympathy for Carol Ernst, and she suffered a tragic loss, as anyone would suffer when there is a sudden death in the family," said Merck lawyer Jonathan Skidmore to CNN/Money. "But that's not our case. Vioxx has nothing to do with her husband's death."

Ernst's suit is the first of more than 4,100 filed against Merck since the withdrew Vioxx on Sept. 30, 2004, after the drug raised concerns that it increased the risk of heart attacks and strokes. The outcome of the Ernst case is important, because it serves as a precedent for thousands of others.

"What we've got to show at the courthouse is what actually occurred: that Merck acted responsibly every step of the way, from discovery of the new drug to testing it to putting it on the market," said Skidmore.

Lanier said that Ernst will be cross examined Thursday afternoon.

Ernst's daughter Shawna Sherrill wept on the stand Wednesday as she described the impact of her stepfather's death on her mother. "The night Bob died, we lost my mom, too," said Sherrill to the jury, according to Lanier. "She's very depressed."

The plaintiff divorced her first husband in the early 1980s and raised her four children as a single mother until 1997, when one of her daughters set her up with Robert Ernst. They were married within three years, according to Lanier.

Legal expert Chip Babcock, a lawyer with the Houston firm Jackson Walker and chair of the Texas Supreme Court advisory committee, said the emotional testimony alone won't decide the case, but it could be an effective coup de grace to Merck if the jurors are already convinced by the plaintiff's story.

"If the jury is looking at it through the plaintiff's rose-colored glasses, then the emotional testimony will have an impact and it will drive damages in favor of the plaintiff," said Babcock. "But if [Lanier] hasn't demonstrated his case, he's not going to get these jurors."

Though Lanier has not specified the damages he is seeking, analyst Chris Shibutani of J.P. Morgan Chase has estimated that Merck's liabilities from all cases could range from $8 billion to $25 billion.

Merck has never conceded that the drug caused anyone's death and has consistently denied accusations that it concealed information about the drug's risks.

Vioxx, an arthritis painkiller, made $2.5 billion in annual sales before it was pulled from the market. Based in Whitehouse Station, N.J., Merck had $22.9 billion in 2004 sales.

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