"From 1999 to 2007, the number of U.S. poisoning deaths involving any opioid analgesic (e.g., oxycodone, methadone, or hydrocodone) more than tripled, from 4,041 to 14,459, or 36% of the 40,059 total poisoning deaths in 2007. In 1999, opioid analgesics were involved in 20% of the 19,741 poisoning deaths. During 1999–2007, the number of poisoning deaths involving specified drugs other than opioid analgesics increased from 9,262 to 12,790, and the number involving nonspecified drugs increased from 3,608 to 8,947."

Source

"Number of Poisoning Deaths Involving Opioid Analgesics and Other Drugs or Substances — United States, 1999–2007," Morbidity and Mortality Weekly Report, August 20, 2010, Vol. 59, No. 32 (Atlanta, GA: US Centers for Disease Control), p. 1026.