Pharmaceutical giant Merck and Co. was saddled with two doses of negative news on Tuesday, the first reporting that the company abruptly canceled a clinical trial to study the heart risks of its now defunct painkiller Vioxx. The second report alleged that company executives were concerned about elevated mercury levels in Merck’s childhood vaccinations - nearly a decade before the first public disclosure.

The Vioxx report, in The New York Times, said Merck was poised to begin a major cardiovascular study of the arthritis drug in 2002, some two years before the drug was withdrawn from the market over concerns about an increased risk of heart attack and stroke.

The trial had been scheduled to produce data by March 2004, and may have hinted at a problem even earlier, the newspaper said.

Merck said it canceled the trial because other ongoing tests would have supplied the same answers, the Times reported. Merck also said it decided not to do the study because it involved high-risk patients with a condition called acute coronary syndrome, involving chest pain caused by cardiovascular disease.

In September 2004, Vioxx was pulled from the market after a separate study found Vioxx patients had heart attacks and strokes at twice the rate of people who took a non-medicinal placebo.

The vaccine allegations, contained in a 1991 memo obtained by the Los Angeles Times, said senior Merck executives were concerned about 6-month-old infants getting doses of mercury that were up to 87 times the recommended dietary amount obtained from eating fish. The mercury was contained within a widely used sterilizing agent called thimerosal, the newspaper said.

Federal health officials disclosed in 1999 that some infants were being exposed to high levels of mercury through routine vaccinations. At the time, the FDA said it was engaging in the first-ever effort to assess just how much mercury children were being exposed to. The Merck memo showed that at least one major manufacturer was aware of such concerns much earlier, the Los Angeles Times report said.

Some 4,200 claims have since been filed against Merck and other vaccine makers by parents asserting that their children acquired autism or other neurological conditions caused by the vaccines. Thimerosal has largely been removed from pediatric vaccines in recent years, the newspaper said.