Plaintiffs' attorneys stepped up pressure on Merck on cases related to its withdrawal of Vioxx, the anti-inflammatory drug, sending the US drugmaker's shares plummeting again on Monday.

Senate investigators examining Merck's recall of its Vioxx painkiller have interviewed an Alabama lawyer whose firm has filed 58 lawsuits against the company on

Shares of Merck & Co. plunged again Monday after a news report suggested the drug maker attempted to keep safety worries from hurting the prospects of Vioxx before the company finally recalled the painkiller.

Amid growing concern about litigation over Vioxx, the painkiller yanked off the market, Merck & Co. shares fell nearly 10% and Standard & Poor's Rating Services placed the company's triple-A corporate credit and senior unsecured debt rating on watch with negative implications.

Merck & Co.'s shares fell nearly 10 percent, to the lowest price in almost nine years, after The Wall Street Journal reported that the drug maker tried for years to stop safety concerns from hurting sales of its blockbuster arthritis drug Vioxx.

Plaintiffs' attorneys stepped up pressure on Merck on cases related to its withdrawal of Vioxx, the anti-inflammatory drug, sending the US drugmaker's shares plummeting again.

Shares of Merck & Co. plunged again after a news report suggested the drug maker attempted to keep safety worries from hurting the prospects of Vioxx before the company finally recalled the painkiller.

Surveying the wreckage of the worst pharmaceutical tort litigations of the past, investors naturally want to know: Will Vioxx be the next Baycol, or Rezulin, or fen-phen? Our prediction is: yes, but bigger.

Plaintiffs' attorneys are predicting that Merck & Co.'s recall of Vioxx will significantly enhance their odds of convincing jurors that the popular arthritis medication caused their clients' heart attacks and strokes.

Merck's press conference was very disappointing, according to Andy Birchfield, "Instead of accepting responsibility for putting a dangerous drug on the market and keeping it there for so long, Merck spent an hour defending itself."