HOUSTON -- A federal judge in Houston will meet next week with the lawyers in the first federal Vioxx trial to set a date for a retrial of the lawsuit against the maker of the painkiller.

As jurors began their fourth day of deliberations Monday, the judge found them to be deadlocked and declared a mistrial, saying, "We cannot get a verdict."

They had deliberated for 18 hours over three days.

Merck and Co. already has won a round and lost a round in state courts and faces thousands of other expected lawsuits related to Vioxx. The drug was pulled from the market last year after being linked to cardiovascular problems.

Jurors were considering whether Merck was negligent in designing Vioxx, and whether the company failed to warn the public about the drug's risks.

The case centered on the May 2001 death of Richard "Dicky" Irvin Jr., a Florida man who had a fatal heart attack a month after he started taking Vioxx to alleviate back pain. His wife, Evelyn Irvin Plunkett, claims in her lawsuit that her husband was in "very good health" when he started taking the once-popular painkiller, reported KPRC-TV in Houston.

"I knew in my heart that my husband had died because of Vioxx, and I had to push forward for that," said Irvin's wife said.

Merck, the maker of the drug, argued that Vioxx was not a factor in Irvin's death because he took the drug for a few weeks. Irvin got the prescription for Vioxx from his son-in-law, an emergency-room physician, without a medical checkup.

Merck blamed Irvin's death on clogged arteries and a blood clot that led to the heart attack.

"Merck had acted responsibly when they developed Vioxx and brought it to the market. We think the evidence also shows that taking Vioxx, 25 mg for such a short period of time, could not possibly have contributed to Mr. Irvin's heart attack," said Merck attorney Philip Beck.

Beck said the retrial will probably take place in February in New Orleans. He said he has "no clue" about how or why the jury was divided.

Jere Beasley, Plunkett's attorney, said a new trial could start as early as Tuesday but will probably not happen until early 2006.

"(We are) obviously disappointed because we felt like we were going to win the case, but now we are going to have to try it again," Beasley told KPRC.

Beasley said he's looking forward to a new trial. He pointed to last week's revelation that Merck had withheld damaging data on the drug. That development wasn't made known to jurors.

He hopes to convince a new judge that profits from Merck's executives should be admitted as evidence in the trial.

"The marketing information was rather limited in this trial, but in the next trial, because of all their misconduct, I believe the judge is going to let this in."

Merck, based in Whitehouse Station, N.J., pulled Vioxx from the market in September 2004 after a study showed it could double the risk of heart attack or stroke if taken for 18 months or longer.

The drug, prescribed to relieve acute pain and arthritis while cutting the risk of stomach bleeding, went on the market in 1999 and reached peak sales of $2.5 billion a year.

Merck faces about 7,000 state and federal lawsuits and billions of dollars in potential payouts for judgments, settlements and legal fees.

Merck has vowed to fight most of litigation, though the company has said it will consider settling lawsuits that involve long-term Vioxx usage.