NEW YORK (CNN/Money) - The tally of Vioxx-related lawsuits against drug giant Merck increased dramatically over the last three months, the company said Thursday.

Product liability lawsuits involving the arthritis painkiller Vioxx now total 4,100, said Graeme Bell, Merck's senior director of investor relations, to analysts during a second-quarter conference call on Thursday. Bell said these lawsuits represent 7,500 plaintiff groups.

This number is about an 80 percent increase from the last corporate tally, which was approximately 2,300 lawsuits representing 4,600 plaintiff groups. Merck said that some of these actions are coordinated through multidistrict legislation in the U.S. District Court in Louisiana, and state courts in New Jersey and California.

"It's certainly not a shock to me, and I don't think it would be a shock to anyone on Wall Street that the number of lawsuits has increased," said Anthony Butler, analyst for Lehman Brothers. Butler said the number of lawsuits filed is less relevant to Merck's potential damages than the outcome of the first case against the company, which began in a Texas state courtroom on July 11.

"Does it increase the amount of money for which Merck is liable?" said Butler. "I would say no, because Merck hasn't been proven to be liable for anything."

David Moskowitz, analyst for Friedman, Billings, Ramsey & Co., said the initial number of lawsuits "seemed low," and he expected the number to rise. Moskowitz said that, according to some lawyers, a two-year statute of limitations from the time the drug was recalled allows plenty of time to file more lawsuits.

Moskowitz and Butler cited an estimate from Judge Eldon Fallon of the federal court in Louisiana, who reportedly projected that Vioxx lawsuits could total 100,000.

"The decline in earnings is a lack of incentive to own the stock near term," said Moskowitz. "And of course, the looming risk of Vioxx litigation makes it that much more of a hot potato to own."

Merck's (down $0.68 to $31.18, Research) stock price fell more than 2 percent following the earnings report.

Merck pulled Vioxx, a $2.5 billion drug, off the market on Sept. 30, 2004, in response to concerns the medication could cause heart attacks and strokes. The company, however, has never conceded there were risks.

The first lawsuit went to trial July 11 in an Angleton, Texas, state court. Plaintiff Carol Ernst blames Merck for the death of her husband, a Vioxx patient. Her lawyer, W. Mark Lanier of Houston, said that Vioxx caused the fatal cardiac arrhythmia of Robert Ernst and Merck suppressed information about the dangers of the drug.

Merck has consistently denied charges that Vioxx caused deaths on the grounds that these charges have never been proved. Merck has also denied allegations that it concealed information, noting that the company voluntarily withdrew Vioxx from the market.

Bell said the company has set aside $675 million for litigation costs, though this does not include potential settlement costs. This figure has remained unchanged since Dec. 31, 2004, despite the increase in lawsuit filings.

Christ Shibutani, analyst for J.P. Morgan Securities, has estimated that Merck's potential liability damages could range from $8 billion to $25 billion. Shibutani was not immediately available to say whether he'd change his estimate based on the escalating tally that was reported Thursday.

Merck blamed the Vioxx withdrawal and a tax charge for its drop in second-quarter profit. The company earned $721 million, or 33 cents per share, in the second quarter, down from $1.8 billion, or 79 cents per share, during the same period last year. Sales dropped 9 percent to $5.5 billion from $6 billion.

Based in Whitehouse Station, N.J., Merck is one of the largest drugmakers with $22.9 billion in 2004 sales.

Butler does not own Merck stock, though Lehman has done business with the company. Moskowitz does not own Merck stock, though Friedman, Billings, Ramsey & Co. may have done business with the company.

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