Allergan Plc sued Pfizer Inc. to cover any potential damages that the drugmaker might be forced to pay as a result of the hundreds of lawsuits it faces over its alleged role in the opioid crisis.

Allergan claims the allegations in the opioid litigation involve improper marketing and sale of sale of morphine drug Kadian in the years before it acquired the rights to it. Allergan, then known as Actavis Plc, acquired Kadian in December 2008 from a company that was later acquired by Pfizer.

The lawsuit was filed Aug. 1 in Cleveland federal court, where most of the litigation has been consolidated for proceedings before U.S. District Judge Dan Polster. Opioid makers and drug wholesalers are accused of creating a public-health crisis through their marketing of the painkillers. The companies recognize there’s an opioid crisis, but have said they aren’t responsible and litigation is the wrong way to address the issue.

Pfizer said it would review the lawsuit and respond accordingly.

“Allergan’s claims relate to a product that Pfizer never manufactured, marketed or sold,” Pfizer said in a statement. “Instead, they arise from a historical 2008 contract belonging to King Pharmaceuticals, a company we acquired in 2010.”

Allergan and other companies such as Purdue Pharma LP and McKesson Inc. could be facing huge damages to resolve the litigation. Polster has encouraged the sides to reach a global settlement, which Bloomberg Intelligence has estimated could be $50 billion. Plaintiffs’ lawyers have compared the situation with the historic $246 billion settlement in Big Tobacco.

Allergan said in its lawsuit that Actavis agreed to assume only some liabilities, and that King agreed to indemnify any liabilities involving Kadian sales and marketing before 2009. Allergan and Pfizer later inherited these obligations, according to the lawsuit.

“But now that more than a thousand lawsuits seek to impose liability for that very marketing and sale, Pfizer has rejected any responsibility to indemnify Allergan,” according to the lawsuit.

The damages include the costs and legal fees that Allergan has already spent defending claims in lawsuits and civil investigations based on marketing and sales before 2009, according to the lawsuit. Madison, New Jersey-based Allergan said it sells less than one-tenth of one percent of all prescription painkillers in the U.S.