ANGLETON, Texas — A Texas jury found pharmaceutical giant Merck & Co. liable yesterday for the death of a man who took the once-popular painkiller Vioxx, awarding his widow $253.4 million in damages in the first of thousands of lawsuits pending across the country.

The panel of seven men and five women in Angleton, a town about 45 miles south of Houston, deliberated for 10 1/2 hours over two days before returning the verdict in a 10-2 vote.

Plaintiff Carol Ernst began to cry when the verdict was read.

"I'm relieved," Ernst said, a calm and tired contrast to her lawyer's gleeful shouts of "Amen! Amen!" when the verdict was read.

"This has been a long road for me. But I felt strongly that this was the road I needed to take so other families wouldn't suffer the same pain I felt at the time," she said.

The damage award is likely to be drastically cut to no more than $26.1 million because Texas law caps the punitive damages that made up the bulk of the total.

Jurors rejected Merck's argument that Robert Ernst, 59, died of clogged arteries rather than a Vioxx-induced heart attack that led to his fatal arrhythmia.

"They know truth and they know justice," Mark Lanier, lawyer for Ernst's widow, said of the jury. "Anyone who said they are too small-town or won't understand, they are crazy."

Robert Ernst, who had been taking Vioxx for eight months, was a produce manager at a Wal-Mart store. He ran marathons and taught aerobics classes on the side.

The case drew national attention as a signal of what lies ahead for Merck, which has vowed to fight the more than 4,200 state and federal Vioxx-related lawsuits pending across the country. Merck said it plans to appeal.

Ernst called the verdict a "wake-up call" for pharmaceutical companies.

After news of the late-afternoon decision, Merck shares fell 7.7 percent to close at $28.06, wiping away almost $5.2 billion in market capitalization.

Merck lawyer Jonathan Skidmore said the appeal would center on what he termed "unreliable scientific evidence."

"It'll be based on the fact that we believe unqualified expert testimony was allowed in the case; there were expert opinions that weren't grounded in science, the type that are required in the state of Texas," he said. "We don't believe they (plaintiffs) met their burden of proof."

The jury awarded $450,000 in economic damages for Robert Ernst's lost pay, $24 million for mental anguish and loss of companionship and $229 million in punitive damages.

But the punitive damage amount is likely to be reduced since state law caps punitive damages at twice the amount of economic damages — lost pay — and up to $750,000 on top of noneconomic damages, which are composed of mental anguish and loss of companionship.

That would give Ernst a maximum of $1.65 million in possible punitive damages, meaning her total damage award could not exceed $26.1 million.

Merck pulled Vioxx, a $2.5 billion seller, from the market in September 2004 when a long-term study showed it could double risk of heart attack or stroke if taken for 18 months or longer.

Vioxx inhibits an enzyme known as Cox-2, which thins the blood. That feature allows it and other drugs in its class — Pfizer's Bextra and Celebrex — to relieve acute pain and arthritis without causing stomach bleeds or ulcers, as painkillers such as aspirin can.

The Ernst case centered on an autopsy that attributed his death to an arrhythmia secondary to clogged arteries. That autopsy — and the coroner who performed it — proved critical to the verdict.

Merck pointed to the autopsy as proof that Vioxx could not have caused the death of Ernst.

However, Dr. Maria Araneta, the pathologist who performed Ernst's autopsy, testified for Ernst that a blood clot that she couldn't find probably caused a heart attack that triggered Ernst's arrhythmia. She also said the heart attack killed Ernst too quickly for his heart to show damage.

While Araneta couldn't say definitively that he had a blood clot and heart attack, she insisted they were the likely culprits in triggering an arrhythmia, which she said wouldn't happen on its own.

An FDA expert advisory panel voted in February that Vioxx could be allowed back on the market for selected patients, but yesterday's verdict made that possibility more remote.

In November, the first of 1,800 federal cases will be heard in New Orleans. The case concerns Richard Irvin, a Florida man who was taking Vioxx for a month before his 2001 death from a blood clot in his heart.

Andrew Birchfield, plaintiff's attorney in that case and co-lead counsel for the committee overseeing the 4,500 federal Vioxx lawsuits already filed, said the decision bodes well for other people who may have been harmed by Vioxx. As many as 20 million people took Vioxx worldwide, and semi-official estimates of the number of people possibly injured or killed have reached above 100,000.

"The Texas case was a hard one because of that coroner's report pointing to arrhythmia as the cause of death," he said. "But the jury took that information, and all they heard about Merck's bad conduct, and they came to the conclusion that Vioxx caused the death and the company needed to be punished."

Next month, Merck faces a trial in Atlantic City, N.J., brought by Michael Humeston, a former postal worker, who had a heart attack in 2001. Humeston's lawyer, Chris Seeger, said Humeston still has lingering effects from the attack.

The Washington Post contributed to this story.