MEDFORD, Ore. — Attorneys representing both living and deceased patients of an Oregon hospital filed a $303 million lawsuit against the facility on Tuesday after a nurse was accused of replacing prescribed fentanyl with nonsterile tap water in intravenous drips.

The wrongful death and medical malpractice complaint accuses Asante Rogue Regional Medical Center in Medford of negligence. The suit says the hospital failed to monitor medication administration procedures and prevent drug diversion by their employees, among other claims.

A spokesperson said the hospital had no comment.

Dani Marie Schofield, a former nurse at the hospital, was arrested in June and charged with 44 counts of second-degree assault. The charges stemmed from a police investigation into the theft and misuse of controlled substances that resulted in patient infections. She has pleaded not guilty.

Schofield is not named or listed as a defendant in the complaint filed Tuesday. A separate suit was filed against Schofield and the hospital earlier this year on behalf of the estate of a 65-year-old man who died.

The 18 plaintiffs in the new suit include nine patients and the estates of nine patients who died. According to the suit, the hospital began informing them in December that an employee had replaced fentanyl with tap water, causing bacterial infections.

“All Plaintiff Patients were infected with bacterium uniquely associated with waterborne transmission,” the complaint says.

All of the plaintiffs experienced mental anguish, according to the suit, which seeks millions of dollars in damages for medical expenses, lost income and the pain and suffering of those who died.

Medford police began investigating late last year, after hospital officials noticed a troubling spike in central line infections from July 2022 through July 2023 and told police they believed an employee had been diverting fentanyl.

Fentanyl is a powerful synthetic opioid that has helped fuel the nation’s overdose epidemic, but it is also used in legitimate medical settings to relieve severe pain. Drug theft from hospitals is a longstanding problem.