Patterns of oxycodone controlled-release use in older people with cancer following public subsidy of oxycodone/naloxone formulations: An Australian population-based study

Aim: Public subsidy of the oxycodone/naloxone controlled release (CR) combination in December 2011 expanded the overall market for oxycodone CR in the general public in Australia; we evaluate its impact in people with cancer.Methods: We used Repatriation Pharmaceutical Benefits dispensing data linked with the NSW Cancer Registry for Department of Veterans' Affairs (DVA) healthcare card holders 65 years and older residing in NSW between 2004 and 2013 to identify clients with cancer and their opioid dispensings. We used interrupted time series analysis to model changes in monthly rates of oxycodone CR tablets dispensed and initiations. We performed a retrospective cohort study to examine changes in client characteristics and opioid utilization over time by comparing clients initiating oxycodone CR before and after subsidy.Results: The rate of oxycodone CR tablets dispensed/month increased by 20% from December 2011, due to uptake of the oxycodone/naloxone CR combination; monthly initiations increased immediately by 17%. Initiations of buprenorphine, fentanyl, and morphine declined from December 2011. DVA healthcare card holders were significantly more likely to initiate the 5 mg oxycodone CR formulation; more likely to use immediate release oxycodone in the 90 days following initiation; and less likely to use a weak opioid in the 90 days preceding oxycodone CR initiation following December 2011 than they were prior to that time.Conclusions: The public subsidy of the oxycodone/naloxone CR formulation expanded the overall oxycodone CR market for DVA healthcare card holders with cancer. Our findings highlight the need for updated guidelines around risk management for opioid treatment in patients with cancer.