LOS ANGELES -- Houston rapper Pimp C died of an overdose of prescription cough syrup combined with the effects of a pre-existing sleep disorder, the L.A. County Coroner said Monday.

Pimp C, whose real name was Chad Butler, was found dead in a Sunset Strip hotel Dec. 4.

Assistant chief coroner Ed Winter said the death was accidental.  Initial reports indicated the cough syrup in Butler’s system was over-the-counter, but officials later determined the substance was a prescription medication.

Butler had Promethazine and Codeine in his system at the time of his death. 

Winter said Codeine cough syrup hampers one’s respiratory abilities.  Those drugs, combined with Butler’s sleep apnea, were enough to kill the 33-year-old rapper.

MySpace.com

Pimp C

Butler was half of the rap duo UGK, Houston-based artists who spun searing tales of Texas street life into a key role in the rise of Southern hip-hop.

Butler and Bun B formed UGK while the two were in high school in Port Arthur.

Their often laconic delivery paired with wittily dangerous lyrics influenced a generation of current superstars like Lil’ Wayne. T.I. had the group on as guests when he remade their 1994 song “Front, Back and Side to Side” for his “King” album.

To a mainstream audience, Pimp C was best known for UGK’s cameo on the Jay-Z hit “Big Pimpin’,” and for “Free Pimp C” T-shirts and shout-outs, ubiquitous in rap several years ago while he was jailed on gun charges.

Though they never enjoyed massive pop chart success, UGK’s early CDs are considered landmarks for the then-burgeoning Texas hip-hop scene, which also featured the Geto Boys. Signed to a deal with Jive Records, they released “Too Hard to Swallow” in 1992, “Super Tight” two years later, and “Ridin’ Dirty” in 1996, considered a rap classic.

Over laid-back beats, they laid out incisive details that remain Southern rap mainstays: descriptions of sex and conspicuous consumption, wood-grain steering wheels and triple-beam scales used to weigh drugs.

The duo’s career was derailed when Pimp C was jailed for three years in 2002 on gun charges. But he got as much exposure as ever, as the “Free Pimp C” slogan spread.

An unauthorized album of Pimp C’s freestyle rhymes was released while he was in prison. When he and Bun B finally put out an album this year, they felt such a need to re-establish themselves they titled their album “Underground Kingz,” as if to underscore a new start.

Critics praised the CD, which included the hit “International Player’s Anthem (I Choose You),” featuring OutKast. Pimp C’s verse riffs on high-class women and cars: “I’m pullin’ Bentleys off the lot. Smashed up the gray one, bought me a red. Everytime we hit the parking lot we turn heads,” he raps.

Butler is survived by his wife and three kids.

The Associated Press contributed to this report.