Merck & Co. (MRK) on Thursday took a major victory in the case of its controversial painkiller, Vioxx, with a New Jersey jury deciding the drug maker had adequately warned consumers of risks associated with Vioxx (search).

As a result, Merck will not be held liable for the 2001 heart attack suffered by a postal worker who had taken the drug.

After deliberating for less than eight hours over three days, the jury cleared Merck of allegations that it failed to inform consumers about potential risks and engaged in "unconscionable commercial practices" in marketing it to medical professionals and patients.

Jurors voted 8-1 that Merck properly warned doctors about risks with Vioxx and voted unanimously on three counts that Merck did not mislead doctors about the drug's safety.

“I think the evidence is very clear that with short-term use” the risks are lower, Merck lead attorney Jim Fitzpatrick (search) said in a televised interview.

Merck's stock rose $1.35, or 4.8 percent, to $29.76 in afternoon trading after the verdict.

Plaintiff Frederick "Mike" Humeston (search) showed no visible reaction as he heard the verdicts. After the jury left the room, he turned and hugged his wife, Mary.

“The plaintiffs are clearly the underdogs," plaintiff's attorney Mark Lanier said in a televised interview.

“It's typical in a mass court case for the company to win the first dozen that come out the box,” he said, adding, "I have full confidence in the jury."

Members of Merck's legal team, some with tears in their eyes, hugged each other after the jury left the room.

"I feel pretty good," said Merck lead counsel Diane Sullivan. "I'm proud of the folks at Merck."

The verdict is Merck's first win of two Vioxx-related trials. In August, a Texas jury found the company liable in a Vioxx user's death. Damages there will be cut to about one-tenth of the jury's $253 million award due to that state's caps on punitive damages.

Much of the seven-week trial, eagerly watched by attorneys and plaintiffs involved in similar Merck lawsuits around the nation, relied on the testimony of medical experts.

Witnesses for Merck testified that the company believed Vioxx was safe for the heart before the drug was pulled from the market a year ago, after a study showed it doubled risk of heart attacks and strokes when taken for at least 18 months.

The company faces more than 6,500 similar lawsuits. Merck has said it plans to fight the product liability suits one by one.

The Texas and New Jersey cases have drawn national attention from pharmaceutical companies, lawyers, consumers and stock analysts, all of whom are trying to determine what lies ahead for Merck.

The New Jersey verdict capped a trial centering on Humeston, 60, of Boise, Idaho, who was stricken two months after he began taking the drug to ease pain from a Vietnam war knee injury.

Merck's lawyers appeared to be fighting a losing battle, repeatedly clashing with Superior Court Judge Carol E. Higbee, who denied key motion requests by them and threw out the testimony of Merck's first witness on procedural grounds.

On five different occasions, Merck asked her to declare a mistrial. Each time, she refused.

In the end, that turned out to be a blessing — and a much-needed one — for Merck.

The six-woman, three-man jury concluded that Merck adequately disclosed information about the drug's risks and could not be held accountable for Humeston's heart attack.

Humeston's lawyers painted a picture of the two-time Purple Heart winner as a victim of a greedy drug company that put profits before patients, rushing Vioxx to market in an unsuccessful bid to beat rival Celebrex onto drugstore shelves.

About 20 million Americans took Vioxx after it hit the market in 1999, embracing it for its effectiveness in relieving pain while sparing them the upset stomachs, ulcers and other gastric problems associated with some other analgesics.

At its peak, Vioxx was a $2.5 billion-a-year blockbuster.

It worked for Humeston, alleviating pain in his left knee, which sustained shrapnel injuries during his U.S. Marine Corps service in Vietnam. But on Sept. 18, 2001, Humeston took two Vioxx pills after work and within hours suffered a mild heart attack.

His doctors blamed it on Vioxx, saying Humeston — a hiker and former mountain guide — had clear arteries and no history of heart disease. He wouldn't have taken it had he known about the heart attack risk, lawyer Chris Seeger told jurors.

Seeger said he was "absolutely surprised" by the verdict.

"I have to kind of sit and reassess what went wrong here. My desire to try more cases is way up right now," Seeger said. "Merck is based in New Jersey. Maybe that factored into this jury pool."

Only one juror, casino worker Juan Garcia, voted that Merck failed to give adequate warnings to doctors about the link between Vioxx and increased risk of heart attacks and strokes.

"I think they should have known and explained more to the doctors and everyone," Garcia said. He said he also believed Vioxx was a factor in causing Humeston's heart attack.

But Vickie Heintz, who works in a manufacturer's credit department, said she believed stress and Humeston's other health problems were responsible for his heart attack.

"I thought he had way too many health other issues," Heintz said. "His medical records were riddled with many medicines."

Merck repeatedly reminded jurors that the U.S. Food and Drug Administration had approved it as safe and effective on four occasions for use against different types of pain, the last incident happening a month before Merck recalled it.

The company's lawyers cited Humeston's elevated blood pressure, weight and stress from an ongoing dispute he was having with his U.S. Postal Service bosses, saying they were to blame for his heart attack, not Vioxx.

The night before the heart attack, Humeston was called by his personal physician in response to an office visit by Postal Service fraud investigators in which they showed him a secretly recorded videotape of Humeston working on a car at his home.

Merck's expert cardiologist testified that that call was the "absolute trigger" for the heart attack.

While Humeston made for a sympathetic plaintiff, he also was a relatively healthy one, appearing in court nearly every day of testimony and taking the stand for one day.

In the Texas case, the victim was a Wal-Mart produce manager who died after taking Vioxx; his widow was the plaintiff.

Merck's lawyers also told jurors there was no scientific link between short-term Vioxx use and heart attacks.

The Associated Press contributed to this report.