A jury awarded $9 million in punitive damages on Tuesday to a man who blamed his heart attack on Vioxx, finding that manufacturer Merck & Co. failed to warn about the risks of its arthritis drug and misrepresented the risks to physicians.

The damages are in addition to $4.5 million already awarded to John McDarby, 77, of Park Ridge, who suffered a heart attack after four years on Vioxx, a painkiller taken by 20 million Americans before being pulled off the market.