A Texarkana doctor was arrested Tuesday on allegations stemming from his prescribing practices.

Dr. Lonnie Joseph Parker of Texarkana was arrested on suspicion of nine counts of distribution of a controlled substance to a patient without an effective prescription. Parker over two years allegedly prescribed about 1.2 million opioids to 1,508 patients — approximately 847 dosage units per patient — and 16 gallons of promethazine with codeine cough syrup to about 29 patients, according to a Western District of Arkansas news release.

Drug Enforcement Administration investigators first probed the allegations in 2018 after receiving complaints from local law enforcement about a possible pill mill and overdose death of a patient. The investigation showed Parker overprescribed substances including opioids, benzodiazepines and promethazine with codeine cough syrup in the area, the release states.

Parker will be arraigned Wednesday in federal court, said U.S. Attorney Duane "DAK" Kees.