The maker of best-selling arthritis pain reliever Celebrex (search) said it plans to immediately stop advertising the drug.

The move comes after a study showed high doses of Celebrex were associated with an increased heart attack risk.

New York-based Pfizer Inc. (PFE) spent more than $70 million advertising Celebrex to U.S. consumers in the first nine months of this year.

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

The move covers television, radio, newspaper and magazine advertising, Pfizer spokeswoman Mariann Caprino said.

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

Pfizer said it plans to keep Celebrex on the market and will continue marketing the drug to doctors.

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

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.

News of the increased heart risk for Celebrex patients came in one of two long-term cancer-prevention trials.

The National Cancer Institute (search), 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.

The heart-attack findings for Celebrex come only 10 weeks after Merck & Co. (MRK) pulled Vioxx (search), a rival drug that is also a COX-2 inhibitor, from the market because it doubled the risk of heart attack and strokes in patients taking the medication longer than 18 months.

Moody's Investors Service (search) revised its outlook on Pfizer to negative from stable because it believes Celebrex use may decline as the controversy about the class increases. Moreover, it said the likelihood that the drug could be pulled from the market may have risen and Pfizer's litigation may increase.