Use of analgesics following rescheduling of codeine in Australia: An interrupted time series analysis in the veteran population

Abstract

BackgroundThe Australian medicines regulator, the Therapeutic Goods Administration (TGA), rescheduled all codeine-containing medicines to be available only on prescription on 1 February 2018. This study was conducted to determine whether use of analgesics changed following codeine re-scheduling to prescription only status, and whether there was a change in the use of codeine preparations and a therapeutic shift to stronger opioids or other analgesics in the Australian veteran population following the change. MethodsInterrupted time series analysis using Repatriation Pharmaceutical Benefits Scheme (RPBS) claims data from the Australian Government Department of Veterans’ Affairs (DVA) for clients with dispensing of opioid and non-opioid analgesics between January 2015 and April 2019. Trends in the monthly rate of analgesic dispensings (opioid and non-opioid) were compared for the period between January 2015 and January 2018 with the period February 2018 to April 2019. ResultsParacetamol with codeine 8mg was the only analgesic with an increased rate of dispensing following the February 2018 codeine scheduling changes. Prior to codeine re-scheduling, the rate of dispensing of paracetamol with codeine 8mg was decreasing by 0.9% each month. Immediately after the scheduling changes, dispensing of paracetamol with codeine 8mg increased by 45% (95%CI=1.282-1.676, p<0.001) and in the fifteen month period thereafter (February 2018 to April 2019), the rate of dispensing increased by 4% each month (95%CI=1.027-1.054, p<0.001). Therapeutic shift from over-the-counter codeine products to other opioids was not observed, with no increase in the rate of dispensing of any of the other opioid (or non-opioid) analgesics following the codeine scheduling changes. ConclusionA significant increase in prescription use of paracetamol with codeine 8mg was observed after the February 2018 codeine re-scheduling. Therapeutic shift to stronger opioid analgesics was not observed in the study population.