Position statement on slow release opioids

The use of slow-release opioids in the management of acute pain has become commonplace despite overseas guidelines warning against the practice.

ANZCA has written to 34 of Australia's and New Zealand’s leading medical colleges and associations including the Royal Australian College of General Practitioners, the Royal Australasian College of Physicians, the Royal Australasian College of Surgeons and the Australian Medical Association as part of an opioid information campaign. The campaign highlights that slow-release opioids are not recommended for use in the management of patients with acute pain. The inappropriate use of slow-release opioids for the treatment of acute pain has been associated with a significant risk of respiratory depression, resulting in severe adverse events and deaths. The letter can be found here.

The harm that can result from opioids initiated in hospital is evident from increasing reports of adverse events.

The use of slow-release (SR) opioids in the management of acute pain has become commonplace despite overseas guidelines warning against the practice. However, an Australian/NZ opinion has been lacking, with many prescribers unaware that they are often prescribing contrary to product licencing and warnings. 

Examples of tragic adverse outcomes can be found in coroners’ reports. These cases highlight the fact that using regularly administered SR opioids added to a PCA or PRN opioid regimen can carry the same risk as adding an intravenous background infusion to a PCA, that is increased risk of respiratory depression, better described as opioid-induced ventilatory impairment (OIVI). In these cases, sedation was often not recognised as an early sign of OIVI, especially when respiratory rate was within the “normal” range.

The death in 2014 and subsequent coroner’s report of an opioid-naive young man who was admitted with acute-onset debilitating headache also highlighted educational needs. These include failure to realise that pain not responding to immediate-release (IR) opioids does not make SR opioids more likely to work, as not all acute pain is opioid responsive. The importance of regularly checking on a patient’s level of sedation was again a relevant feature.

The management of acute pain should allow rapid titration (up or down) of analgesia, as interpatient opioid requirements vary enormously, even for the same type of surgery or injury. Furthermore, acute pain associated with trauma or surgery can fluctuate significantly within short time periods and often decreases rapidly after the initial onset. The slow-onset and sustained effects of SR opioids make rapid titration impossible and side effects (if encountered) unpredictable and possibly very long-lasting.

In 2016, guidelines published by the Centre of Disease Control and Prevention (CDC) specifically warned against using SR opioids in the management of acute pain. More recently, a guide to opioid prescribing published by the Royal Australian College of General Practitioners (RACGP) similarly notes that only IR opioids should be used in the treatment of acute pain in the general practice setting.

FPM and the ANZCA Safety and Quality Committee recognised that a joint statement was needed to start to effect change in the hospital setting. A working group was formed to draft the statement. This statement was then revised and endorsed by FPM and subsequently the ANZCA Safety and Quality Committee. This document does not constitute a guideline, but a statement of opinion designed to inform and recommend.

It is recognised that change cannot happen without stakeholder engagement, and plans are under way to involve other medical colleges and professional bodies as well as the media. It is time that we start to take greater responsibility for our role as often the initiating prescribers, and for both the acute and chronic sequalae. Anaesthetists are ideally placed to lead stewardship over the use of opioids in the management of acute pain.

Future areas of document development include guidance on discharge opioid prescribing and ongoing use of these medications after discharge. A formal request was made by the RACGP to collaborate with the Faculty of Pain Medicine on this matter.

Dr Kim Hattingh, Professor Pamela Macintyre, Professor Stephan Schug, Dr Meredith Craigie and Dr Phillipa Hore


Dowell D, Tamara MH, Chou R. CDC Guideline for Prescribing Opioids for Chronic Pain – United States 2016. MMWR Recommendations and Reports March 18, 2016;  65(1):1-49 https://www.cdc.gov/mmwr/volumes/65/rr/pdfs/rr6501e1.pdf
Royal Australian College of General Practitioners (2017) Prescribing drugs of dependence in general practice. Part C: Opioid prescribing, https://www.racgp.org.au/your-practice/guidelines/drugs-of-dependence-c/

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