A jury in California could not reach a decision on the third of a series of questions on a verdict form in the consolidated cases of two men who blamed their heart attacks on the painkiller Vioxx, leading Judge Victoria Chaney of the Superior Court of California for Los Angeles County to declare a mistrial Thursday. The jury could not determine whether the plaintiffs' physicians would have recognized possible risks and side-effects of the drug. The lawsuits, brought by Arizona resident Lawrence Appell of Arizona and California resident Rudolph Arrigale, claimed that Vioxx was a significant cause of the men's heart problems.

Vioxx manufacturer Merck Pharmaceuticals, which withdrew the drug from the market in 2004 after research showed it doubled the risk of heart attacks and strokes, claimed that the men's heart problems were caused by pre-existing coronary heart disease, and not the drug. After the mistrial was declared, Merck announced that the plaintiffs did not prove their cases, and that they were ready to defend against the allegations if they were brought fourth again. As of the end of last November, Merck faced 27,200 lawsuits over Vioxx and another 265 potential state-based class-action lawsuits. A federal judge rejected national class-action lawsuits in federal court early in November.