A seven-man, five-woman jury deliberated for 10-and-a-half hours over two days before returning the verdict. Merck said it plans to appeal, reported the Associated Press.
The jurors rejected Merck's argument that Robert Ernst died of clogged arteries rather than a Vioxx-induced heart attack that led to his fatal arrhythmia. He was 59 when he died.
The damages award combined Ernst's lost pay as a Wal-Mart produce manager, mental anguish, loss of companionship and punitive damages.
The plaintiff's lawyer, Mark Lanier, said he expects Texas law limiting punitive damages would reduce the award from $253 million to $229 million, according to Reuters.
The case drew national attention from pharmaceutical companies, lawyers, consumers and stock analysts as a sign of what may lie ahead for thousands of other related lawsuits filed across the country.
If the first wave of trials ends in verdicts against Merck, experts predict it will open the floodgates for more lawsuits and could force the drug company to settle cases. If Merck prevails, it could curb future lawsuits, the AP reported.
Merck said it was disappointed in the verdict and is looking at grounds for appeal.
"We believe that we have strong points to raise on appeal and are hopeful that the appeals process will correct the verdict," said Kenneth Frazier, senior vice president and general counsel for Merck, in a statement. "Our appeal is about fundamental rights to a fair trial."
Merck pulled Vioxx from the market on Sept. 30, 2004, after data from a clinical trial showed an increased risk for heart attacks and strokes.
Vioxx was first marketed as a drug that reduced internal inflammation, which causes pain in the body. It had been on the market since FDA approval in 1999.
The announcement came after a three-year trial designed to evaluate the efficacy of taking the drug in preventing a recurrence of colorectal polyps in patients with a history of benign colorectal tumors, the company said.
Merck found that after 18 months of treatment, patients taking Vioxx were at greater risk for heart attacks compared with those taking a placebo.
The results confirmed the findings of an FDA investigator who reported similar risks with the drug in August 2004.