GRUNDY CENTER, Iowa (AP) -

An Iowa doctor has been cleared of criminal charges alleging he ran an unauthorized methadone clinic.

Dr. Frank Lamp, of Grundy Center, was cleared this week in Grundy County District Court of nine misdemeanor charges. He was formally charged last April.

Methadone is a narcotic commonly prescribed as a painkiller but can also be used to wean addicts off heroin or other drugs. Lamp was accused of writing prescriptions to three patients without a special required permit.

The Des Moines Register reports Lamp says he was always confident he'd be cleared.

Lamp still faces administrative charges from the Iowa Board of Medicine. He is scheduled to appear before the board next week.