- Purdue Pharma LP, which launched OxyContin in 1996, filed for bankruptcy protection Sunday night, succumbing to pressure from more than 2,600 lawsuits alleging the company helped fuel the U.S. opioid epidemic. Purdue's board met Sunday evening to approve the long-expected bankruptcy filing, which the company is pursuing to restructure under terms of a proposal to settle widespread litigation.

- Nearly 400,000 deaths in the United States have been linked to overdoses of opioids from 1990 to 2017, according to the U.S. Centers for Disease Control and Prevention. About 218,000 of those deaths have been from prescription opioids, while the rest were from illicit opioids including heroin.

- The problem is getting worse: the number of opioid-related deaths in 2017 was six times higher than in 1999, according to the CDC.

- Approximately 2,500 lawsuits over opioids are currently pending. The first such lawsuit to survive a motion to dismiss was filed in 2014 by the city of Chicago. Since then, thousands of individuals, numerous cities and every state but Nebraska have brought legal claims over opioids.

- About 2,000 of the pending lawsuits, most brought by municipalities and counties, have been consolidated before a federal judge in Cleveland, Ohio. That judge, U.S. District Judge Dan Polster, has ruled that the cases may proceed to trial but has pushed for a "global" settlement to resolve all of the claims, and recently approved a novel procedure that will allow plaintiffs' lawyers to negotiate on behalf of a class of all municipalities and counties in the country.

- Besides Purdue, the drug companies targeted by the lawsuits include Johnson & Johnson, Teva Pharmaceutical Industries Ltd and Endo International Plc.

- Many lawsuits also target wholesale drug distributors, including AmerisourceBergen Corp, McKesson Corp and Cardinal Health Inc.

- Outside of the Ohio litigation, most lawsuits are pending in state courts, particularly ones brought by state attorneys general. Most target Purdue. Many also name members of the wealthy Sackler family, which owns Purdue.

- Some cases have already resulted in verdicts. An Oklahoma judge in August ordered Johnson & Johnson to pay $572 million in a lawsuit brought by the state's attorney general for the company's role in the opioid epidemic.

- While most opioid lawsuits that have been filed remain pending, a few have settled. Oklahoma previously reached a $270 million settlement with Purdue and an $85 million settlement with Teva. Reckitt Benckiser agreed to pay $1.4 billion to settle federal and state claims related to its drug Suboxone.

- Purdue has reached a tentative settlement with some plaintiffs in the mass litigation. However, because of its bankruptcy filing, any settlement may have to be worked out in bankruptcy court.

- Several criminal cases have also been brought in connection with prescription opioids. New York-based distributor Rochester Drug Co-operative Inc paid $20 million to resolve federal criminal charges. A unit of Massachusetts-based Insys Therapeutics pleaded guilty to federal criminal charges and paid $225 million before declaring bankruptcy, and some of the company's executives have been convicted of fraud. A criminal case remains pending against Ohio-based distributor Miami-Luken Inc.

(Reporting by Brendan Pierson in New York; Editing by Paul Simao)

By Brendan Pierson