Drug giant Pfizer announced Sunday that it is pulling all advertisements for its popular pain reliever Celebrex. This comes two days after Pfizer admitted that studies showed high doses of the drug led to an increased risk of heart attacks. But Pfizer is keeping the drug on the market and the company will still market the drug to doctors. The watchdog group Public Citizen called on the Food and Drug Administration to ban Celebrex and another drug, Bextra. According to Public Citizen, researchers have known for years that drugs like Celebrex can increase the risk of heart attacks.