PHILADELPHIA — The company that makes OxyContin did not stop pitching the powerful opioid painkiller to doctors even when its sales representatives raised concerns that they were prescribing the drug inappropriately, the Pennsylvania attorney general’s office said in a lawsuit announced Tuesday.

The lawsuit against Connecticut-based Purdue Pharma was filed on May 2 under seal and announced on Tuesday. It made Pennsylvania at least the 39th state to sue the company seeking to hold it responsible for the toll of opioids, which have been killing more people in the U.S. and Pennsylvania each year than car crashes.

The suit says Purdue drug representatives have made 531,000 detailing calls on doctors in the state since 2007, when the company settled with Pennsylvania and 25 other states agreeing to stop identifying illegal diversion of its OxyContin and to promote it only for federally approved uses.

The suit names several doctors whom the state says the company continued to call on to promote opioids despite signs that they were prescribing to addicts or worrying pharmacies with their prescribing levels. The complaint singled out one — Philadelphia doctor Jeffrey Bado — as one of the nation’s biggest prescribers of opioids. The doctor lost his license in 2013 and was convicted in 2016 crimes including causing the death of a patient.

The state says the company stopped calling on Bado at points because of concerns over his prescribing practices but kept returning again to promote the drugs.

Purdue denies the allegations.

Around 2,000 local governments, including several in Pennsylvania, along with unions, hospitals and Native American tribes have also sued various industry players including Purdue and other drugmakers, distributors and pharmacies.

Purdue, a privately held company based in Stamford, Conn., earlier this year publicly threatened bankruptcy as the litigation mounts. For 2017, the U.S. Centers for Disease Control and Prevention tallied a record of nearly 48,000 opioid deaths.

In Pennsylvania, the state Health Department said that more than 4,200 people died of overdoses involving any drug last year, down from nearly 5,600 in 2017.