A sales representative for Insys Therapeutics Inc., the opioid maker that has been the subject of mounting litigation of late, pleaded guilty in New Jersey on Wednesday to her part in an alleged scheme in which doctors were bribed to increase off-label prescriptions of painkiller Subsys.

The guilty plea comes as the state continues to pursue litigation against the Arizona-based pharmaceutical company, which has become the central target of the state's efforts to combat opioid abuse.

Michelle Breitenbach, 38, of Middletown, a New Jersey-based sales rep for the company, pleaded guilty before Middlesex County Superior Court Judge Benjamin Bucca Jr. to a second-degree charge of conspiracy to commit commercial bribery, according to the Attorney General's Office.

A release said Breitenbach admitted that she participated in a scheme in which doctors, in return for off-label prescribing of Subsys, were paid kickbacks and bribes in the form of purported speaker fees for marketing and education events.

Breitenbach, the release said, faces a possible prison sentence of up to five years.

According to the release, doctors participated in the speaking engagements supposedly to inform other doctors about Subsys, but speakers were paid regardless of whether they spoke or if no one attended. Breitenbach claimed she was pressured from above at Insys to push the speaking programs, the office said.

Breitenbach's lawyer, Nicholas Harbist at the Princeton office of Blank Rome, didn't return a call for comment.

The state has alleged in a lawsuit that the founder of Insys, John Kapoor, and his company  engaged in an illegal campaign to push sales of Subsys, a potent pain medication typically reserved for cancer patients. They are accused in the civil complaint of endangering the public through efforts to push drug sales illegally. The state alleges that two New Jersey state employee health benefit plans paid a total of approximately $10.3 million to reimburse Subsys prescriptions between 2012 and the third quarter of 2016, while the state workers' compensation program paid another $300,000. The lawsuit claims violation of the New Jersey Consumer Fraud Act and the New Jersey False Claims Act. The suit asks that Insys and Kapoor be assessed civil penalties, treble damages, and fees and costs.

The state's complaint alleges that Insys's corporate decision-makers, led by Kapoor, devised a strategy to expand what they recognized as a limited market for Subsys by aggressively pushing off-label uses of the drug, even to podiatrists and other specialty practitioners who typically would have little call to treat cancer patients or prescribe powerful Schedule II painkillers.

From the 2012 market launch of Subsys until the present, the drug has accounted for approximately 98 percent of net revenues for Insys, a Delaware corporation with headquarters in Chandler, Arizona, according to the suit. Insys, which has raised the price of Subsys every year since its launch, sold $74.2 million worth of the drug in New Jersey between 2012 and the third quarter of 2016, the state claims.

Several other government entities have sued Insys as well, including, most recently, Minnesota, according to reports.

Kapoor previously pleaded not guilty in Boston to charges that he led a conspiracy involving doctors to overprescribe the painkiller.