LOS ANGELES (AP) — The state Medical Board did not violate patients' privacy when it dug through their medication records while investigating their doctor, the California Supreme Court ruled Monday.

The board had good reason to search a statewide prescription drug database without a warrant or subpoena while investigating a Burbank doctor who was placed on probation for prescribing excessive levels of powerful drugs, the court said in a unanimous ruling.

The ruling amid a nationwide epidemic of opioid abuse pitted the government's ability to investigate overprescribing by doctors with patient privacy rights.

At issue was a statewide database established to allow doctors to make sure patients aren't receiving too many drugs and lets regulators and law enforcement investigate doctors who may be overprescribing controlled substances.

The court said investigators could obtain the records for discipline and policing purposes and didn't have to show good cause because that would hamper efforts to ferret out abuse.

"Requiring the board to present evidence to a judicial officer establishing good cause as part of its preliminary investigations could result in protracted legal battles that effectively derail those investigations," Justice Goodwin Liu wrote. "Delays ... would impede the board's ability to swiftly identify and stop dangerous prescribing practices."

Dr. Alwin Lewis was investigated after a patient who saw him about low iron and fatigue had complained that the physician suggested she go on his "five bite diet."

While the board found Lewis didn't provide improper care to that patient, investigators discovered problems with his prescribing history. An administrative law judge later found he acted unprofessionally, committed negligent acts and failed to keep adequate records.

The board adopted the judge's recommendation to put him on probation for three years.

Lewis challenged the discipline on grounds that the state intruded on the privacy of his patients by looking at their medication records.