A former Tennessee doctor pleaded guilty Monday to unlawfully distributing controlled substances and could face up to 20 years in prison.

Dr. Darrel Rinehart, who ran a clinic in Columbia, Tennessee, for decades before moving to Indianapolis, admitted to knowingly distributing hydrocodone to a patient who did not have health issues justifying the prescription in 2016, according to U.S. Attorney Don Cochran of the Middle District of Tennessee. He also admitted to distributing opioids and other substances to four patients without a medical purpose on 18 other occasions in 2014 and 2015.

© Tennessee Secretary of State public records Dr. Darrel Rinehart prescribes Adderall to a patient in an undercover video shot in his clinic in Columbia, Tenn., in 2016. Tennessee officials suspended Rinehart's license after he had five patients die from overdoses in less than a year.

Rinehart, who was expected to plead guilty, had five patients die of fatal overdoses within a year. He was indicted on 19 counts of distribution of a controlled substance in March.

Start the day smarter. Get all the news you need in your inbox each morning.

Rinehart will be sentenced on July 30, 2020, by Chief U.S. District Judge Waverly Crenshaw Jr. In addition to time in prison, he could face up to a $1 million fine.

Reach Jamie McGee at 615-259-8071 and on Twitter @JamieMcGee_.

This article originally appeared on Nashville Tennessean: Ex-Tennessee doctor who had five patients die of overdoses pleads guilty to unlawful drug distribution