Jurors in Atlantic City, N.J., assessed punitive damages of $27.5 million against Merck & Co. for marketing its painkiller Vioxx without properly warning of its significant cardiovascular risks.

The punitive award came late on Monday, hours after the jury found that the drug and the failure to warn contributed to plaintiff Frederick Humeston’s heart attack, which occurred five months before Merck changed the product’s label and three years before the product was taken off the market.