Medical outcomes associated with prescription opioid abuse via oral and non-oral routes of administration

Background: Prescription opioid abuse and misuse is a serious and growing public health issue. While the most common form of abuse is swallowing intact tablets/capsules, some abusers manipulate, or tamper with, these medications by altering the dosage form to allow for non-oral routes of administration (e.g., injection, inhalation) in order to achieve more rapid or enhanced psychoactive effects. Because administration of opioids via non-oral routes results in greater systemic availability and more rapid central nervous system penetration, we hypothesized that death and major medical outcomes occur more frequently with non-oral routes compared to oral route alone. Methods: This retrospective cohort study analyzed data from the Researched Abuse, Diversion and Addiction Related Surveillance (RADARS) System Poison Center Program to investigate relative risk of prescription opioid abuse via oral and non-oral routes. Results: While the oral route was the most commonly reported route of abuse (64.0%), non-oral routes were reported in 14.6% exposures and unknown routes in 21.4% exposures. The relative risk of an exposure resulting in death or major effect was 2.43 (95% CI 1.97, 2.99) if non-oral routes were reported compared to exposures involving oral route only. Conclusion: Analysis of acute health events recorded by poison centers indicates that death or major effects are twice as likely to occur with intentional abuse of prescription opioids via non-oral routes of administration than ingestion alone. Effective interventions to prevent abuse via non-oral routes of solid dosage forms of prescription opioids, such as abuse-deterrent formulations could have a significant public health impact.