The damage award will likely be reduced because of state caps on such awards.
The jury of 10 men and two women deliberated for about seven hours over two days before returning the verdict in favor of the family of Leonel Garza.
The company was ordered to pay $7 million in non-economic compensatory damages and $25 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 non-economic damages, which are comprised of mental anguish and loss of companionship.
Because Garza was retired, the jury awarded no economic damages. That means the most Garza's family could receive under state law is $7.75 million.
"Merck will appeal," spokesman Kent Jarrel said.
The case was the sixth of 11,500 lawsuits to reach a verdict and brings Merck's scorecard in the trials to three wins and three losses.
In the prior two losses, the New Jersey-based pharmaceutical company was ordered to pay one plaintiff $253.4 million, which will be reduced to $26 million under Texas caps on punitive damages; and the other $13.5 million.
Attorneys for Garza said that while Garza had a history of heart problems, his veins had been cleared and a stress test showed less than a 2 percent risk of heart attack within a year. They said he had taken the drug for almost a month before he died in April of 2001.