Peter M. Francisco, 57, was addicted to the painkiller, said a statement the U.S. attorney's office released after a plea hearing in U.S. District Court in Abingdon. Between 2000 and 2009, Francisco issued prescriptions for more than 10,000 Zydone pills to three people who returned the medicine to the dentist for his own use, prosecutors said.

Francisco's attorneys could not be immediately contacted Tuesday afternoon.

Francisco agreed to give up his authority to prescribe drugs and to repay insurance companies and government agencies for the cost of the illegally prescribed medications.

Francisco faces a maximum penalty of 15 years in prison and a $750,000 fine. Sentencing is scheduled for Feb. 23.

-- Mike Gangloff