A Montgomery County psychiatrist who traded cash for medically unnecessary opioid prescriptions is heading to federal prison.

Spiro Y. Kassis, 66, was sentenced Wednesday to four years in prison after pleading guilty to illegally distributing controlled substances, including the opiate painkiller oxycodone. Separately,Kassis agreed to pay $1.4 million to settle a federal civil rights lawsuit and agreed to never again obtain a license for prescribing opioid medication.

U.S. Attorney William McSwain said in a statement that Kassis, who was first arrested by county investigators in 2018, often prescribed multiple, powerful narcotics to the same patients, creating “dangerous cocktails.”

“As a physician, he was well aware of the inherently dangerous nature of the drugs he cavalierly handed out," McSwain said. "Nevertheless, he took advantage of vulnerable people struggling with addiction, all the while sitting comfortably behind a desk, watching the money pile up.”

Kassis’ attorney, John I. McMahon, said the sentence was appropriate for a case that he described as “extremely difficult.”

“This was an individual who for many decades really provided conscientious and good care to people suffering with addiction issues,” McMahon said. “He worked in just about every rehabilitation facility in the area, and unfortunately for a combination of reasons, he went off track. He took responsibility to that by pleading guilty.”

Investigators said Kassis operated a “pill mill” out of his office in East Norriton Township. He would conduct brief appointments with his patients, who would often line up 45 people deep inside the practice, they said.

Kassis wouldn’t perform any examinations, investigators said, and would charge $200 for a prescription for the opiate medications. In some instances, he would conduct the appointments over the phone, and send electronic scrips to the patient’s preferred pharmacy.

Kassis’ prosecution came during a heightened awareness of what Montgomery County District Attorney Kevin Steele has called “rogue doctors” who exacerbate the opioid crisis in the suburbs. Steele created a specialized unit in his office, bankrolled by drug-forfeiture money, to pursue these cases.

Between 2018 and 2019, that unit charged five doctors, including Kassis, with improperly distributing controlled substances. All have pleaded guilty.