Jan 17 (Reuters) -

The U.S. Justice Department on Friday accused pharmacy chain

operator Walgreens Boots Alliance ( WBA ) of contributing to the

U.S. opioid epidemic by filling millions of unlawful

prescriptions for addictive painkillers and other drugs.

The department

intervened

in a whistleblower lawsuit filed in federal court in

Chicago and accused Walgreens of ignoring "red flags" and

filling prescriptions for opioids and other controlled

substances that lacked a legitimate medical purpose.

"These practices allowed millions of opioid pills and

other controlled substances to flow illegally out of Walgreens

stores," Brian Boynton, the head of the Justice Department's

Civil Division, said in a statement.

The lawsuit alleged that by knowingly filling unlawful

prescriptions for controlled substances, Walgreens violated the

Controlled Substances Act. The government also alleged it

violated the False Claims Act when it then sought reimbursement

from federal health care programs, like Medicare, for the

prescriptions.

The lawsuit was announced after Walgreens filed its own

lawsuit on Thursday challenging what it said were new policies

the U.S. Drug Enforcement Administration had unlawfully adopted,

seeking to ensure pharmacies do not dispense controlled

substances for medically illegitimate purposes.

That lawsuit was filed in federal court in Tyler, Texas,

following what Walgreens had described as recently as last week

as active negotiations with the Justice Department for a

potential settlement to resolve claims it improperly dispensed

opioids.

The company's lawsuit targeted what Walgreens called new,

"arbitrary" rules the DEA imposed without going through the

required rulemaking process.

"We will not stand by and allow the government to put our

pharmacists in a no-win situation, trying to comply with 'rules'

that simply do not exist," Walgreens said in a statement.

Walgreens is among the drug manufacturers, distributors,

pharmacy operators and others who have collectively in recent

years agreed to pay about $50 billion to resolve lawsuits and

investigations by states and local governments accusing them of

helping fuel a deadly opioid addiction epidemic in the U.S.

The U.S. Centers for Disease Control and Prevention says

nearly 727,000 opioid overdose deaths occurred from 1999 to

2022.

The Justice Department last month announced a similar

lawsuit against Walgreens rival CVS that accused the

pharmacy chain of filling illegal opioid prescriptions and

contributing to a nationwide epidemic of opioid addiction.

Walgreens in 2022 agreed to pay up to $5.52 billion over 15

years to resolve thousands of lawsuits by state and local

governments accusing the company of fueling the U.S. opioid

epidemic.

Last month, Ohio's top court overturned a $650.9 million

judgment two local counties secured against Walgreens, CVS and

Walmart ( WMT ) in the first case to go to trial nationally over

allegations the pharmacies contributed to the epidemic.

(Reporting by Nate Raymond in Boston, Editing by Alexia

Garamfalvi)