Sounds to me like he overdosed on pain meds like Percocet which is an Opiate pain reducing drug that has been known to kill overtime. ie. stop the heart .
Implicated in deaths
On June 30, 2009, an FDA advisory panel recommended that Percocet, Vicodin, and every other combination of acetaminophen with narcotic analgesics[4] be limited in their sales because of their contributions to an alleged 400 acetaminophen related deaths in the United States each year, that were attributed to acetaminophen overdose and associated liver damage.[5]
In December 2009, the Canadian Medical Association Journal reported a study finding a fivefold increase in oxycodone-related deaths in Ontario (mostly accidental) between 1991 and 2007 that led to a doubling of all opioid-related Ontario deaths over the same period.
Hydrocodone: Respiratory depression, extreme somnolence
progressing towards coma, muscle limpness, cold and clammy skin, slow
heart rate, low blood pressure, abrupt loss of heart function and death
may occur.[2]