MCCLAIN COUNTY -- Charges have been filed against Keith Knox Simmons, 28, of Blanchard, a man state drug agents have identified as Oklahoma's top "doctor shopper."

The charges came from a five-month investigation by the Oklahoma Bureau of Narcotics focusing on prescription fraud and abuse.

Over the past two years, agents say Simmons obtained 4,533 dosage units of pain relievers, mostly hydrocodone (Lortab) from 195 different healthcare professionals filled at 105 separate pharmacies, statewide.

Oklahoma Bureau of Narcotics spokesman Mark Woodward said the arrest is due to the Bureau's Prescription Monitoring Program that identified Simmons as Oklahoma's number one drug seeker.

Simmons was charged with four counts of obtaining a controlled dangerous substance by fraud in McClain County and four counts of the same in Garvin County. He has also been charged with one count of engaging in a pattern of criminal offenses in McClain County.

He could face a maximum of 20 years in prison and a $250,000 fine.

"An estimated 87,000 Oklahomans are non-medically using prescription drugs," Woodward said. "Of the 612 drug-related deaths in 2008, 87% involved prescription drugs."