Drug maker Pfizer said it would immediately stop advertising its best-selling arthritis pain reliever Celebrex to consumers after a study showed high doses of it were associated with an increased heart attack risk. This includes all television, radio, newspaper and magazine advertising. Pfizer said it plans to keep Celebrex on the market and will continue marketing the drug to doctors.

The U.S. Food and Drug Administration, which said it was considering warning labels for Celebrex or withdrawing the drug from the U.S. market, agreed with Pfizer's decision to halt advertising.

"We discussed it with the FDA, and we all concurred that it was the appropriate step," Pfizer spokeswoman Mariann Caprino told The New York Times.

Celebrex has not been shown to be dangerous to arthritis patients when taken at normal doses, according to Pfizer. The heart attack risk found occurred when patients took the drug at two to four times the usual dose for many months.

New York-based Pfizer Inc. spent more than $70 million advertising Celebrex to U.S. consumers in the first nine months of this year. Sales of Celebrex and a related drug, Bextra, had been expected to total more than $4 billion worldwide in 2004, nearly 10 percent of Pfizer's revenue.

The National Cancer Institute, which was conducting the study for Pfizer, said patients in the clinical trial taking 800 milligrams of Celebrex had a 3.4 times greater risk of cardiovascular problems compared with a placebo.

For patients in the trial taking 400 milligrams of Celebrex, the risk was 2.5 times greater. The average duration of treatment in the trial was 33 months.