WASHINGTON — The US government sued Rite Aid Corp on Monday, accusing the pharmacy chain of overlooking “red flags” as it illegally filled hundreds of thousands of prescriptions for controlled substances, including opioids.

in a complaint filed in Cleveland federal courtThe Justice Department said Rite Aid repeatedly filled prescriptions from May 2014 through June 2019 that were medically unnecessary, for unauthorized use, or not issued in the usual course of professional practice.

“The Department of Justice is using every tool at our disposal to confront the opioid epidemic that is killing Americans and tearing apart communities across the country,” Attorney General Merrick Garland said in a statement.

Rite Aid pharmacists were accused of ignoring obvious signs of misuse, including in prescriptions for «trinities,» a combination of opioids, benzodiazepines and muscle relaxants favored by drug addicts for their increased euphoric effect.

The Justice Department also said Rite Aid intentionally removed internal warnings from some pharmacists about suspicious prescribers, such as «cash-only pill factory,» while advising them to «be mindful of everything that’s put in writing.»

“These practices opened the floodgates for millions of opioid pills and other controlled substances to illegally leave Rite Aid stores,” said Assistant Attorney General Vanita Gupta.

Rite Aid is one of the nation’s largest drugstore chains, with more than 2,330 stores in 17 US states. It did not immediately respond to requests for comment.

The Justice Department charged Rite Aid with violating the federal False Claims Act by submitting false prescription claims to government health care programs such as Medicare and Medicaid.

It joined a whistleblower lawsuit filed in 2019 by two pharmacists and a pharmacy technician from Rite Aid stores in Pennsylvania, North Carolina and West Virginia.

The Department of Justice occasionally joins whistleblower cases it deems to be the strongest.

It also sued Walmart Inc and drug distributor AmerisourceBergen Corp for their supposed roles in the nation’s opioid crisis.

More than 500,000 people died of drug overdoses in the United States between 1999 and 2020, including more than 90,000 in 2020 alone, according to the US Centers for Disease Control and Prevention.