CVS Pharmacy Inc. is being sued by the U.S. Department of Justice for allegedly filling illegal prescriptions and seeking reimbursement from federal health care programs for unlawful medications.

CVS, the largest pharmacy chain in the U.S. with 9,000 pharmacies across the country, is accused of knowingly filling "prescriptions for controlled substances that lacked a legitimate medical purpose, were not valid, and/or were not issued in the usual course of professional practice," according to a Justice Department news release.

The complaint unsealed Wednesday in the District of Rhode Island says among the large number of illegal prescriptions that CVS allegedly filled were prescriptions for "dangerous and excessive quantities of opioids, early fills of opioids and 'trinity' prescriptions." Trinity prescriptions are a "dangerous and abused" cocktail of drugs made up of an opioid, a benzodiazepine (a depressant drug) and a muscle relaxant.

In a statement emailed to USA TODAY, a CVS spokesperson said, "We have cooperated with the DOJ’s investigation for more than four years, and we strongly disagree with the allegations and false narrative within this complaint."

"We will defend ourselves vigorously against this misguided federal lawsuit, which follows on the heels of years of litigation over these issues by state and local governments—claims that already have been largely resolved by a global agreement with the participating state Attorneys General," the statement continued.

Holiday deals: Shop this season’s top products and sales curated by our editors.

Party City is going out of business:See full list of store closures

CVS allegedly ignored pill mills, evidence from own pharmacists

According to the U.S. Attorney's Office, CVS also allegedly filled large quantities of prescriptions for controlled substances written by prescribers it knew participated in "pill mill practices."

Pill mills are illegal on-site pharmacies that prescribe large numbers of controlled substances to patients who do not need them for any medical purpose, the National Library of Medicine said.

Although CVS had "substantial evidence from multiple sources, including its own pharmacists and internal data," the pharmacy ignored that its stores were dispensing illegal prescriptions, according to the complaint.

“When lives are destroyed or lost to opioid abuse, it doesn’t matter if the supplier is a street-level dealer, a pill mill, or a nationwide corporation,” U.S. Attorney Jessica D. Aber for the Eastern District of Virginia said in the release. “Our laws regarding the dispensing of opioids and other controlled substances are clear and apply to everyone. We will pursue whatever legal action is necessary to stop any enterprise, regardless of size, that places profit over the safety of our citizens.”

DOJ: 'CVS' actions helped to fuel the opioid crisis'

By CVS allegedly ignoring evidence and violating both the Controlled Substances Act (CSA) and False Claims Act (FCA), the pharmacy reached corporate-mandated performance metrics, received incentive compensation and abided by staffing policies that "prioritized corporate profits over patient safety," the Justice Department said.

CVS's staffing levels were far too low for pharmacists to meet their performance metrics and comply with their legal responsibilities, according to the U.S. Attorney's Office. The pharmacy also "deprived its pharmacists of crucial information," including not warning them about certain prescribers.

"The complaint alleges that CVS’ actions helped to fuel the opioid crisis and that, in some particularly tragic instances, patients died after overdosing on opioids shortly after filling unlawful prescriptions at CVS," the Justice Department release reads.

Whistleblower brought allegations against CVS to light

The Justice Department called Hillary Estright, a former CVS employee, a whistleblower after she filed an action on Oct. 17, 2019, alleging misconduct by the pharmacy. She filed under the qui tam provisions of the FCA, which authorizes private parties to sue on behalf of the U.S. for false claims and share in any recovery, the Justice Department said.

The FCA also allows the U.S. to intervene and take over lawsuits filed under qui tam provisions, which is what it has done in this case.

'Unlawful' prescriptions were for an FDA-approved opioid medication, CVS says

According to CVS' statement, the pharmacy said the government's lawsuit is seeking to "impose a shifting standard for pharmacy practice."

"Many of the litigation theories laid out in the complaint are not found in any statute or regulation, and relate to topics on which the government has declined to provide guidance," the statement reads.

CVS also said the prescriptions that the Justice Department is calling "unlawful" were for an FDA-approved opioid medication prescribed by a practitioner who "the government itself licensed, authorized, and empowered to write controlled-substance prescriptions," according to the statement.

According to the statement, CVS Health created a "first-of-its-kind program to block controlled-substance prescriptions written by doctors of potential concern" 12 years ago. To date, the pharmacy has blocked more than 1,250 practitioners, including 600 prescribers who the government continues to license, the statement says.

"This program is not required by any statute or regulation, and CVS Health repeatedly has defended lawsuits from those alleging we go too far in blocking opioid prescribers." according to CVS. "The government’s lawsuit intensifies a serious dilemma for pharmacists, who are simultaneously second-guessed for dispensing too many opioids, and too few."