title: Methods and predictors of tampering with a tamper-resistant controlled-release oxycodone formulation.
abstract: BACKGROUND
  In April 2014, a tamper-resistant controlled-release oxycodone formulation was introduced into the Australian market. This study aimed to identify the level and methods of tampering with reformulated oxycodone, demographic and clinical characteristics of those who reported tampering with reformulated oxycodone, and perceived attractiveness of original and reformulated oxycodone for misuse (via tampering).
  
  
  METHODS
  A prospective cohort of 522 people who regularly tampered with pharmaceutical opioids and had tampered with the original oxycodone product in their lifetime completed two interviews before (January-March 2014: Wave 1) and after (May-August 2014: Wave 2) introduction of reformulated oxycodone.
  
  
  RESULTS
  Four-fifths (81%) had tampered with the original oxycodone formulation in the month prior to Wave 1; use and attempted tampering with reformulated oxycodone amongst the sample was comparatively low at Wave 2 (29% and 19%, respectively). Reformulated oxycodone was primarily swallowed (15%), with low levels of recent successful injection (6%), chewing (2%), drinking/dissolving (1%), and smoking (<1%). Participants who tampered with original and reformulated oxycodone were socio-demographically and clinically similar to those who had only tampered with the original formulation, except the former were more likely to report prescribed oxycodone use and stealing pharmaceutical opioid, and less likely to report moderate/severe anxiety. There was significant diversity in the methods for tampering, with attempts predominantly prompted by self-experimentation (rather than informed by word-of-mouth or the internet). Participants rated reformulated oxycodone as more difficult to prepare and inject and less pleasant to use compared to the original formulation.
  
  
  CONCLUSIONS
  Current findings suggest that the introduction of the tamper-resistant product has been successful at reducing, although not necessarily eliminating, tampering with the controlled-release oxycodone formulation, with lower attractiveness for misuse. Appropriate, effective treatment options must be available with increasing availability of abuse-deterrent products, given the reduction of oxycodone tampering and use amongst a group with high rates of pharmaceutical opioid dependence.
authors.affiliation: School of Medicine, University of Tasmania, Hobart, Tasmania, Australia. Electronic address: Amy.Peacock@utas.edu.au.
authors.forename: Amy
authors.initials: A
authors.lastname: Peacock
authors.affiliation: National Drug and Alcohol Research Centre, University of New South Wales, NSW, Australia.
authors.forename: Louisa
authors.initials: L
authors.lastname: Degenhardt
authors.affiliation: National Drug and Alcohol Research Centre, University of New South Wales, NSW, Australia.
authors.forename: Antonia
authors.initials: A
authors.lastname: Hordern
authors.affiliation: National Drug and Alcohol Research Centre, University of New South Wales, NSW, Australia.
authors.forename: Briony
authors.initials: B
authors.lastname: Larance
authors.affiliation: National Drug and Alcohol Research Centre, University of New South Wales, NSW, Australia.
authors.forename: Elena
authors.initials: E
authors.lastname: Cama
authors.affiliation: Sydney Medical School, Sydney University, NSW, Australia; University of Adelaide, South Australia, Australia.
authors.forename: Nancy
authors.initials: N
authors.lastname: White
authors.affiliation: National Drug and Alcohol Research Centre, University of New South Wales, NSW, Australia.
authors.forename: Ivana
authors.initials: I
authors.lastname: Kihas
authors.affiliation: School of Medicine, University of Tasmania, Hobart, Tasmania, Australia.
authors.forename: Raimondo
authors.initials: R
authors.lastname: Bruno
mesh_terms: D000328:Adult; D016739:Behavior, Addictive / Q000523:psychology*; D003692:Delayed-Action Preparations; D004304:Dosage Forms; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010098:Oxycodone / Q000008:administration & dosage* / Q000009:adverse effects; D019966:Substance-Related Disorders / Q000517:prevention & control*
chemical_list: D003692:Delayed-Action Preparations; D004304:Dosage Forms; D010098:Oxycodone
keywords: Abuse deterrence; Injecting drug use; Opioid dependence; Pharmaceutical opioids; Post-marketing surveillance; Tamper-resistant formulations