Merck & Co. concluded its defense of the latest Vioxx product-liability trial on Monday, saying that two men who blame the withdrawn pain drug for their heart attacks had a series of pre-existing health problems that caused their attacks.

Christy Jones, lead attorney for the drugmaker, said in closing arguments that both plaintiffs had serious coronary blockages that had been building up for years, and that those were responsible for the heart attacks.

“Both of these men had serious, severe coronary artery disease,” Jones told the jury. “That’s what caused the plaintiffs’ heart attacks.”

At the end of the closely watched Vioxx trial - the first to involve long-term users of the drug - Jones also rejected arguments by the plaintiffs’ attorneys that Merck had ignored the heart risks of Vioxx because it put profits before safety.

She said the company’s top scientists, including Dr. Briggs Morrison and Dr. Alise Reicin, both of whom testified during the trial, had gone to work for Merck because they wanted to find cures for serious diseases.

Jurors were being asked by plaintiffs’ attorneys to accept that, in developing the arthritis and pain medicine, people like Morrison and Reicin had suddenly become dominated by the desire to make money, Jones said.

“It’s not just that they put profits before safety. It’s that at the time they joined Merck they suddenly didn’t care any more. It means that Merck somehow duped doctors all over the country into prescribing the drug,” Jones said.

The plaintiffs are Thomas Cona, 60, of Cherry Hill, N.J., and John McDarby, 77, of Park Ridge, N.J., who both took Vioxx for more than 18 months before it was withdrawn.

Attorneys for Cona and McDarby are scheduled to give their closing arguments on Monday afternoon. The jury is expected to begin deliberating on Tuesday.

Merck voluntarily pulled the $2.5 billion-a-year drug from the market in September 2004 after a study showed it doubled the risk of heart attack and stroke among people who used it for at least 18 months.

The plaintiffs say Merck knew the drug was dangerous years before its withdrawal, and continued to sell it because the company placed profits above safety.

Merck says it thoroughly tested the drug before and after it was approved by regulators.

During the trial, the jury of six women and two men heard that Merck was facing a decline in revenue because patents were expiring on a number of its other drugs, and it was looking for a “blockbuster” drug that would generate at least $1 billion a year in sales.

Merck faces almost 10,000 lawsuits over Vioxx, around half of which are filed in the company’s home state of New Jersey.

In the three trials that have gone to a jury, Merck has so far lost only one, in which a Texas jury awarded $253 million to the widow of a Wal-Mart worker who had used the drug. The widow was represented by Mark Lanier, who represents Cona in the current trial.