Has the rescheduling of modified-release paracetamol in Australia affected the frequency of overdoses?

Michaela J Ryan; Andis Graudins; Nicole O'Shea; Firouzeh Noghrehchi; Anselm Wong

doi:10.1111/1742-6723.14403

Has the rescheduling of modified-release paracetamol in Australia affected the frequency of overdoses?

Emerg Med Australas. 2024 Mar 26. doi: 10.1111/1742-6723.14403. Online ahead of print.

Authors

Michaela J Ryan¹, Andis Graudins^{1

2}, Nicole O'Shea³, Firouzeh Noghrehchi⁴, Anselm Wong^{1

5}

Affiliations

¹ Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Melbourne, Victoria, Australia.
² Monash Toxicology Unit and Emergency Department, Dandenong Hospital, Monash Health, Melbourne, Victoria, Australia.
³ Victorian Poisons Information Centre, Austin Health, Melbourne, Victoria, Australia.
⁴ Translational Australian Clinical Toxicology, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia.
⁵ Department of Critical Care, University of Melbourne, Melbourne, Victoria, Australia.

PMID: 38529697
DOI: 10.1111/1742-6723.14403

Abstract

Objectives: In June 2020, modified-release paracetamol (paracetamol-MR) preparations were up-scheduled from schedule-2 (available in pharmacy) to schedule-3 (available by request to a pharmacist only). The present study aims to ascertain whether up-scheduling affected the frequency of paracetamol-MR overdoses.

Methods: This is a retrospective cohort study of two data sets from 1 June 2017 to 31 May 2022. Monash Health data were extracted using the diagnosis of paracetamol overdose coding and electronic medical records data. Calls regarding paracetamol-MR overdoses to Victorian Poisons Information Centre (VPIC) were extracted from the Poisons centre call database. We used a quasi-experimental research design with interrupted time series analysis to evaluate the immediate impact and change in trend of poisoning-related calls and ED presentations before and after June 2020. The change in proportion of paracetamol-MR cases in both databases was analysed using the Χ² test.

Results: The proportion of paracetamol-MR cases in both data sets did not change. From Monash Health, there was no level change in monthly paracetamol-MR overdose-related presentations following re-scheduling (rate ratio [RR] = 1.08, 95% confidence interval [CI] = 0.57-2.01). There was no change in monthly paracetamol-MR overdose-related calls to VPIC following re-scheduling (RR = 1.05, 95% CI = 0.96-1.14).

Conclusion: The proportion of paracetamol-MR overdoses did not decrease after the up-scheduling to S3. Similarly, the frequency of overdoses by month remained similar. Further limitations on access to paracetamol products may need to be considered.

Keywords: Poisons control centres; analgesics; chemical and drug‐induced liver injury; poisoning; toxicology.