MIDWEST CITY, Oklahoma - A Midwest City doctor has been charged with five counts of second-degree murder over the deaths of at least five patients at her clinic.

Dr. Regan Nichols, an osteopathic physician, is accused of prescribing “controlled dangerous substances” to her patients without a legitimate medical reason, and in excessive quantities, showing an “extreme disregard of human life.” Nichols was affiliated with the physician group Spectra Family Medicine and the hospital AllianceHealth, both located in Midwest City.

All five of the patients went to Dr. Nichols' clinic, Sunshine Medical, located at 2816 Parklawn Drive in Midwest City. A patient tells News 9 this practice has been closed since 2015, the time of the investigation. 

According to the Medical Examiner's office, all five deaths were the result of "multi-drug toxicity." Over the course of their investigation, authorities learned that all five of the individuals who died were given more than 1,800 opioid pills in the same month as their deaths.

Investigators say three of the five "were given a deadly three-drug combination of a narcotic opioid pain reliever, an anti-anxiety drug and a muscle relaxer." All of the drugs were prescribed by Nichols, according to the report.

The arrest warrant indicates there are possibly a total of 10 victims, but at this time Nichols’ is being charged with the death of five patients. Nichols still has her license to practice for now, but no longer has the power to write prescriptions.

“I appreciate the effort from everyone who worked as a team and put this case together. The dangers associated with opioid drugs have been well documented and most doctors follow strict guidelines when prescribing opioids to their patients,” Oklahoma Attorney General Mike Hunter said. “Nichols prescribed patients, who entrusted their well-being to her, a horrifyingly excessive amount of opioid medications. Nichols' blatant disregard for the lives of her patients is unconscionable.”

Nichols was arrested and booked into the Oklahoma County Jail Friday afternoon. Officials say Nichols will be held in lieu of $50,000 bond.

Keep checking with News 9 and News9.com for more information.