PROVIDENCE, R.I. (AP) — A Rhode Island doctor pleaded guilty on Wednesday to accepting kickbacks in return for prescribing a highly addictive fentanyl spray.

Jerrold Rosenberg pleaded guilty in U.S. District Court in Providence to one count each of health care fraud and kickbacks conspiracy.

The case is one of several criminal cases brought around the country against people associated with Insys Therapeutics and the prescribing of Subsys, which is meant only for cancer patients with severe pain.

The doctor admitted on Wednesday that he prescribed Subsys to people who didn't have cancer. He then falsified their records so that insurance companies, including Medicare, would pay for it.

Rosenberg also admitted he conspired with Insys executives and others to receive $188,000 in kickbacks for writing the prescriptions through a sham "speakers program."

A significant portion of Rosenberg's practice in Providence and North Providence dealt with pain management. He was by far the biggest prescriber of fentanyl spray in Rhode Island and one of the top prescribers in the nation, according to the February indictment.

The indictment said that Rosenberg even refused to switch patients to a different drug when they complained of debilitating side effects from Subsys, or when they said it was not working.

A spokesman for Arizona-based Insys says the company is under new management and has replaced nearly all its original sales staff. It says it takes responsibility for the actions of its former employees.

"We have taken necessary and appropriate steps to prevent past mistakes from happening in the future, and are committed to conducting business according to high ethical standards and the interests of patients," the company said in a statement. "We also continue to work with relevant authorities to resolve issues related to the misdeeds of former employees."

In Massachusetts, former Insys CEO Michael L. Babich and five other former executives and managers have pleaded not guilty and are scheduled to go to trial in October 2018. Several former Insys employees and health care providers have also pleaded guilty to felony charges in places around the country, including Alabama and Connecticut.

Rosenberg is scheduled to be sentenced Jan. 16 and faces a maximum 15 years in prison. Prosecutors said they planned to call some of Rosenberg's victims, his former patients, to testify during sentencing.

Rosenberg's son, who has not been charged, was a sales representative for Insys from 2012 to 2013. The majority of his son's compensation stemmed from commissions he received from his father prescribing the drug, the indictment said.

The physician's lawyer, Charles Tamulevitz, told the judge that Rosenberg was not admitting to any conspiracy with his son.