Opioids are narcotics that are used to treat pain. Examples include hydrocodone, oxycodone, codeine, morphine, propoxyphene, meperidine, methadone, and fentanyl. Doctors increasingly prescribe opioids for patients with chronic pain. Overdose and death rates from opioid poisoning are also increasing. However, it is unknown whether overdose is common in patients prescribed long-term opioid therapy for pain.