"By 2002, opioid analgesics were involved in more deaths than either of the illicit drugs responsible for most urban drug abuse in the 1990s: heroin and cocaine. These trends are generally consistent with trends in drug-related emergency department visits reported by DAWN from 1997 to 2002: a 101.4% increase in opioid analgesics, a 23.7% increase in cocaine, and a 32.2% increase in heroin.
"The increased involvement of these analgesics is related to exponential growth in their domestic sales over the past decade as physicians began to treat chronic pain with stronger analgesics.10 Oxycodone sales in grams increased 402.9% from 1997 to 2002; methadone (excluding that used in narcotics treatment programs) increased 410.8%; and fentanyl increased 226.7%.11 OxyContin, introduced in 1996, accounted for 68% of oxycodone sales by 2002."
Paulozzi, Leonard J., "Opioid Analgesic Involvement in Drug Abuse Deaths in American Metropolitan Areas," American Journal of Public Health (Vol 96, No. 10), October 2006, p. 1756.