Investigators say a physician's assistant has been charged with prescription drug fraud. State Bureau of Investigation agents charged 42-year-old Gregory Damon Shanton with obtaining controlled substances by fraud, delivering controlled substances and illegally obtaining a noncontrolled substance. The charges cover the period between 1998 and 2003. The arrest warrants issued this week say the alleged fraud occurred without the knowledge of the physician Shanton worked for. Drugs involved in the charges include 16-hundred doses of Xanax, more than seven thousand milliliters of Tussionex and 240 doses of Paxil. The state Medical Board suspended Shanton's license last year for a month and gave him 12 months to reimburse a medical insurance company.