A New Jersey jury awarded $9 million in punitive damages to a man who blamed his heart attack on Merck & Co’s painkiller Vioxx yesterday, after deciding that the company deliberately withheld information about the drug’s risks from the US Food and Drug Administration.

Last week, the plaintiff, 77-year-old John McDarby, was awarded a further $4.5 million in compensatory damages in the cases, after the jury decided that Merck had failed in its duty to warn doctors and patients about the risks with Vioxx.

Merck, which pulled Vioxx off the market in 2004 after a link emerged between the drug and heart attacks and stroke, said it would launch an appeal against the verdict, which said it acted with ‘wanton disregard’ for patients taking the drug.

The company insists it followed the letter of the law in reporting data to the FDA, but the jury was swayed by the case out forward by McDarby’s lawyers, who questioned why Merck failed to submit a statistical analysis to the agency in 2000 that showed the elevated risks with Vioxx. Merck had argued that the analysis was not robust, and in any case the FDA was provided with all the raw data on which it was based.

The punitive award was not the highest that could have been awarded, as under New Jersey law Merck could have been liable for up to 5 times the compensatory claim, or $22.5 million. But it is a severe legal blow for Merck, and automatically causes the case to be referred to the state attorney general for a possible criminal investigation.

Merck is still facing more than 9,600 lawsuits in state and federal courts, and has insisted that it will fight each case, one at a time.

But the McDarby case has raised the possibility that more plaintiffs could come forward, according to observers. Merck argued that underlying heart disease and other risk factors were the primary cause of his heart attack, but the failure of this defense could encourage lawyers to pursue cases they had previously advised against because their clients had multiple risk factors. It is estimated that 20 million people in the USA took Vioxx between its launch in 1999 and 2004.

After losing a first Vioxx damages case in Texas in which a woman was awarded $253 million, capped at $26 million, Merck won two further cases involving short-term users of the drug. The latest court case was the first to involve long-term users of Vioxx, which is thought to only elevate the risk of heart attack or stroke after long-term exposure of 18 months or more.