Rapper Pimp C’s death in a West Hollywood hotel room was accidental and the result of a combination of factors, including use of prescription medicine used to treat coughs and congestion and sleep apnea, the coroner’s office reported Monday.

The 33-year-old rapper, whose real name was Chad Lamont Butler, was found dead at the Mondrian hotel on Dec. 4.

In a statement issued Monday afternoon, the coroner’s office said Butler’s death was ruled accidental and cited “promethazine/codeine effects and other unestablished factors.”

The case report noted that the rapper had a history of sleep apnea, a chronic disorder in which breathing is briefly suspended repeatedly during sleep.

The promethazine/codeine combination is prescription medicine commonly used for the treatment of a cough and/or congestion, said Assistant Chief Ed Winter of the coroner’s office.

Butler was half of the duo UGK and considered a pioneer of southern rap.