A US District judge on Friday accepted a guilty plea and settlement from Purdue Pharma and three of its exectives over the marketing of its painkiller OxyContin (extended-release oxycodone), and issued a $634.5 million fine. This represents approximately 90% of the profits on sales of OxyContin during the period in which the offense took place, papers from the District Court for Western Virginia said.

The company and three current and former senior executives - president Michael Friedman, chief legal officer Howard Udell and former head of R&D Paul Goldenheim - pleaded guilty in May to charges that the firm deliberately misled the US public about the risk of addiction associated with its painkiller OxyContin.

The plea ended what was a four-year investigation by the US Attorney’s Office. Under the terms of the settlement, Purdue will now agree to pay $470 million to government agencies and $130 million to resolve private civil lawsuits related to the painkiller. In addition, Friedman and Udell will pay fines totalling $19 million and $8 million, respectively, while Goldenheim is being hit with a $7.5 million penalty. All are now convicted criminals and each has been asked to undertake 400 hours of community service and placed on three years' probation; they will also be subject to court supervision. Furthermore, Purdue itself is convicted of a felony and will now have to endure an extensive corporate integrity agreement to ensure it is compliant with all US federal laws.