The booming business of addiction afforded years of luxury to Dr. Joseph Mogan III.

As the head of sham pain clinics in Metairie and Slidell that swapped pills for cash, the physician spared himself no expense, purchasing three Ferraris and a twin-engine plane before the feds finally shut him down. The Hippocratic Oath took a back seat to a lavish lifestyle built on the backs of addicts whose habits Mogan fed like an indiscriminate drug dealer.

He opened a failed nightclub on Tchoupitoulas Street, developed a penchant for child pornography and flew to Europe to visit prostitutes in the Netherlands.

Without even examining his clients, Mogan doled out prescriptions for “the holy trinity,” a cocktail of painkillers that combines hydrocodone, a sedative and a muscle relaxant. The clinics accepted only cash and, for years, seemed to be printing money, raking in some $1.5 million a year.

The family of at least one former client blamed him for a fatal overdose.

“I was greedy,” Mogan told jurors last year after cutting a deal to testify against Donald Nides, a former police officer accused of protecting the pill mills in exchange for cash and sexual favors. “I did it for the money.”

On Wednesday, several months after he pleaded guilty to money laundering and drug conspiracy charges dating back to 2003, Mogan stood before a federal judge and begged for mercy, claiming the community would be “best served by my being able to get back into” medicine as soon as possible, “before I start to lose my skills.”

He also invoked his mother’s health, saying she’s “not safe for driving.”

“I am extremely remorseful and saddened by my actions,” Mogan, 48, said. “I finally feel like I’ve started to atone for my actions, and I know I’ve got a lot of atoning left to do.”

Mogan, who surrendered his medical license last year, faced a 40-year prison term under the federal sentencing guidelines. But prosecutors, in a motion filed under seal, asked U.S. District Judge Susie Morgan to credit Mogan’s extensive cooperation in helping them build a case against Nides, a former New Orleans police officer and U.S. Drug Enforcement Administration task force member who committed suicide in November after the first full day of testimony in his jury trial.

Mogan obliged, sentencing the disgraced doctor to about eight years in federal prison. She meted out the same punishment — 97 months behind bars — to Tiffany Miller, 43, a co-defendant who ran the Omni Pain Management clinics alongside Mogan and forged a sexual relationship with Nides that prosecutors said allowed the pill mill operation to avoid law enforcement attention for years.

Miller’s former husband had owned an interest in the Omni clinics but died of an overdose in 2011, according to court documents.

Before Nides fatally shot himself, Miller had been expected to testify about the oral sex she often performed on him in the kitchen of one of the clinics and, at times, inside his vehicle. She also slipped the crooked cop cash, and, in turn, Nides divulged the DEA’s playbook to her, prosecutors said.

Nides, known at the clinics as “Mr. Don,” had been accused of tipping off Miller to practices that would raise eyebrows among investigators, such as long lines of patients, many from out of state, gathering outside a pain clinic before dawn.

Miller and Mogan applied that advice and other pointers to their business, limiting the number of patients who could sit in their waiting rooms and requiring others to wait in their vehicles. Nides even warned the clinics about prescription patterns that might engender suspicion.

A lawsuit filed in St. Tammany Parish last year alleges that Terrie Debnam had been among Mogan’s clients. The suit claims Mogan plied the Jackson Parish woman with mass quantities of prescription pills on a monthly basis before her overdose death in 2013 — the same year the feds shut down the pill mills.

The suit claims Mogan prescribed Debnam eight different types of medication, including morphine sulfate and butalbital, the day before she was found dead.

On Wednesday, Mogan said he had done a lot of soul searching in recent months.

“I’m very thankful for the prosecutors for closing us down when they did,” he said. “I was miserable for the last five years when I was working there.”

Staff writer Faimon A. Roberts III contributed to this report.

Follow Jim Mustian on Twitter, @JimMustian.