Two days after agreeing to pay states nearly $20 million for falsely marketing OxyContin, the drug's maker, Perdue Pharma, and three current and former executives plead guilty to federal charges. The Stamford, Conn.-based maker of the powerful painkiller, and three of its current and former executives, pleaded guilty Thursday to misleading the public about OxyContin's risk of addiction. Purdue Pharma L.P., its president, top lawyer and former chief medical officer will pay $634.5 million in fines for claiming the drug was less addictive and less subject to abuse than other pain medications, U.S. Attorney John Brownlee said. The plea agreement comes after the company agreed to pay $19.5 million to 26 states and the District of Columbia to settle complaints that it encouraged physicians to overprescribe OxyContin. Even though the company was warned by health professionals, the media and members of its own sales force, Perdue continued to push a fraudulent marketing campaign that promoted OxyContin as less addictive, less subject to abuse and less likely to cause withdrawal when they knew in fact that that was not true," Brownlee told CBS News correspondent Barry Bagnato. "Doctors are often approached right in their offices by pharmaceutical company sales reps dispensing information about one medication or another," said CBS News medical correspondent Dr. Jon LaPook. "This case is a reminder to doctors not to believe everything they hear."