Real World star Joey Kovar died this August 2012 and the cause of his death was believed to be a combination and overdose on cocaine, viagra, and alcohol.  An examiner has revealed that this was not the cause of the death, but opiates were.  The 29-year-old passed away from opiate intoxication and an accident.
Steph B

At the time of his death, Kovar was allegedly taking the prescription painkiller Norco, according to sources.
Norco is classed as an opiate, however it is not confirmed that the medication was responsible for his death.

But now has been confirmed as the painkiller responsible for his death.

[Source]