Background Pain is common amongst cancer patients and is often undertreated. Over the past 30 years the use of opioids has proven an effective treatment, with multiple evidence-based guidelines available. Increasingly, barriers to prescribing opioids have been described both internationally and within Australia and New Zealand, including the supply, availability and access to various opioids.

Objectives This study aimed to describe current practice in opioid prescribing for cancer pain by Palliative Care, Medical Oncology and General Practice clinicians in Australia and New Zealand; identify factors that influence prescribing of opioids; and explore how supply issues have impacted opioid prescribing.

Methods Invitations were circulated via peak bodies to participate in a cross-sectional survey administered online (Qualtrics).

Results 114 doctors responded to the survey (85 Australia, 29 New Zealand). 100 worked in Palliative care, 5 in Medical Oncology, and 13 in General Practice. Morphine and oxycodone were the most commonly prescribed long-acting opioids for cancer pain in both Australia and New Zealand. The most common reasons for selection were availability, cost, and alignment with colleagues’ practice. Most clinicians rarely used weak opioids in the management of cancer pain. There was a high level of experience and self-reported knowledge in prescribing opioids. Factors influencing opioid prescribing included current restrictions in prescribing (85.8%), and potential side effects (82.1%), while only around 25% of clinicians were concerned about addiction or about professional/legal repercussions. When selecting background opioids the patient-factors considered were: mechanism of pain (91.5%), renal function (92.5%) and routes of medication available (92.5%), with the least important factors being marketing (0%) and stigma regarding opioids (31.1%). The most likely factors to trigger opioid rotation were intolerable side effects (100%), inadequate analgesia (99%), and mode of delivery (98.1%). When rotating opioids for cancer pain, most clinicians relied on their own knowledge (91.4%) and/or sought advice from colleagues (54.8%), while only 27.9% sought advice from pharmacists. The most frequently used guidelines were the Palliative Care Formulary, ANZCA opioid calculator and local guidelines. 74.8% of Australian clinicians reported that the supply/availability of opioids impacted their practice last year (2023). Of those, 92.2% report having to choose a less preferred opioid option. Hydromorphone (both long and short-acting) was the most commonly reported medication impacted by availability. Clinicians described wanting to use hydromorphone as a rotation option due to its effectiveness, potency, and particularly for use in patients with renal impairment. Almost all Australian clinicians agreed stronger government policy is needed for consistent opioid supply.

Conclusion Opioid prescribing for cancer pain was largely mechanistic, highly influenced by cost and availability of medications. Despite differences in the availability of opioids in New Zealand and Australia, the most commonly prescribed options were similar. Opioid supply issues are impacting the evidence-based practice of experienced clinicians in Australia and New Zealand. Constructing stronger government policy is recommended for the ongoing safety and efficacy of cancer pain management.