A New York physician has pleaded guilty to a manslaughter charge in connection with a patient's overdose death.

The state attorney general's office said Tuesday that 61-year-old Barry Sloan admitted to providing patients powerful narcotics outside the good faith practice of medicine and to recklessly causing the death of a 36-year-old Manhattan man by prescribing fentanyl.

Prosecutors say Sloan held himself out as a pain management specialist in New York and New Jersey from 2011 through 2016. They say he prescribed mostly "risky and addictive drugs," including oxycodone, over 70,000 times.

Sloan is expected to be sentenced to four to nine years in a state prison. He'll also be required to surrender his license to practice medicine in New York State. Information on his lawyer wasn't immediately available.