The impact of codeine upscheduling on overdoses, Emergency Department presentations and mortality in Victoria, Australia

•Upscheduling of codeine decreased the rate of codeine-related deaths.•Codeine-related poisoning calls decreased post-upscheduling.•Codeine-related Emergency Department presentations decreased post-upscheduling. Prior to February 2018, codeine was available over-the-counter (OTC) in Australia as a pharmacist-only medicine (Schedule 3) in low-strength formulations when in combination with simple analgesics. In February 2018, The Advisory Committee on Medicines Scheduling (ACMS) upscheduled codeine-containing medicines (CCM) to Schedule 4 (prescription-only medicine). This study aimed to determine the impact of upscheduling on prescriptions, overdoses and deaths. This study used interrupted time series analysis, a quasi-experimental design, to retrospectively evaluate the impact of upscheduling on overdose poisoning calls to the Victorian Poisons Information Centre (VPIC), Emergency Department (ED) presentations to Austin Health, and deaths reported to the Victorian Coroner from 1 January 2013–31 December 2019. There was a significant reduction in the trend of high-strength codeine poisoning calls by 0.36 (P = 0.03, 95 % CI = [−0.69, −0.04]). Low-strength codeine poisoning calls to the VPIC reduced by 13.31 (P