Background & Aims

The United Kingdom (UK) lacks any current data on how much opioid medication surgical patients are prescribed on discharge home, nor on how much they use once they have left hospital. A study from the United States (US) by Hill et al [1] of common general surgical procedures found that 70% of opioid tablets dispensed on discharge went unused. The significant healthcare and cultural differences between the US and UK preclude any transferable comparisons to our population so, in this study, we aimed to gather the first UK information on this topic, using patient data from Oxford University Hospitals (OUH). We expanded the protocol of Hill to include 20 procedures, across all types of surgery. We anticipate that these pilot results will reveal the extent of postoperative opioid over-prescribing in the UK, the broad discrepancies in prescribing practices, and inform future recommendations for safer discharge opioid prescribing.

Methods

This cohort study was conducted at a single tertiary centre from April 2023 to January 2024. We reviewed 20 of the most common procedures identified through medical coding searches in the following surgical specialties: trauma and orthopaedics, general, colorectal, hepatobiliary, renal, breast, obstetrics, cardiothoracic and neurosurgery. An average of 20 patients were recruited for each procedure. Exclusion criteria included patients under the age of 16, those with communication difficulties, and patients who had postoperative complications. Patients discharged with at least one opioid were identified through a weekly discharge list using the electronic patient record. Patients were surveyed using a standardised telephone questionnaire at between 6-8 days after hospital discharge to establish opioid consumption. Both consumed and unused opioids were recorded and converted to oral morphine equivalent (OME) for analysis [2,3].

Results

We collected data from 418 patients undergoing one of 20 procedures. Codeine was the most common opioid dispensed, and was the sole opioid for patients undergoing the majority of non-orthopaedic surgeries. Dihydrocodeine was the sole opioid dispensed for caesarean section, while tramadol was the preferred choice after colorectal resection.
Opioid prescribing was more diverse after the orthopaedic procedures with little conformity and more dispensing of stronger opioids – morphine or oxycodone – both of which were typically supplied in liquid form, with volumes ranging from 50 to 250ml. OME dispensed ranged 7-fold (from 84-600mg) among patients after knee arthroplasty, and over 4-fold (84-384) after hip arthroplasty.
In total 52645mg OME was dispensed, with only 38.25% used (20125mg) in the first 7 days after discharge. Median OME use ranged from 0mg after mastectomy to 142mg after total knee replacement. Only 3 patients requested more opioid analgesia from their primary care doctor.

Conclusions

This study is the first to show that current UK discharge opioid dispensing after many surgical procedures is far above opioid requirement, producing a large community burden of unused opioids. The pattern of UK opioid prescribing is very different to US practices and more similar to that of other European countries, with more weak opioids dispensed compared to strong opioids [4]. The smallest pack size available in the UK for codeine 30mg is 28 tablets, which in many cases was far in excess of need. There is a responsibility of pharmaceutical companies to provide smaller pack sizes as standard to improve safety.
Our results demonstrate the need to provide more robust prescribing guidelines, which could be applied nationally. Guidance on post-discharge opioid prescribing must be specific for procedure, population and patient to inform future safer prescribing [5], providing a balance between adequate pain management and risk.

References

1. Hill MV, McMahon ML, Stucke RS, Barth RJ Jr. Wide Variation and Excessive Dosage of Opioid Prescriptions for Common General Surgical Procedures. Ann Surg. 2017 Apr;265(4):709-714. doi: 10.1097/SLA.0000000000001993.
2. https://www.ouh.nhs.uk/services/referrals/pain/opioids-chronic-pain.aspx (accessed 29.1.24)
3. https://fpm.ac.uk/opioids-aware-structured-approach-opioid-prescribing/dose-equivalents-and-changing-opioids
4. Ladha KS, Neuman MD, Broms G, Bethell J, Bateman BT, Wijeysundera DN, Bell M, Hallqvist L, Svensson T, Newcomb CW, Brensinger CM, Gaskins LJ, Wunsch H. Opioid Prescribing After Surgery in the United States, Canada, and Sweden. JAMA Netw Open. 2019 Sep 4;2(9):e1910734. doi: 10.1001/jamanetworkopen.2019.10734.
5. Levy N, Quinlan J, El-Boghdadly K, et al. An international multidisciplinary consensus statement on the prevention of opioid-related harm in adult surgical patients. Anaesthesia. 2021;76(4):520-536. doi:10.1111/anae.15262

Presenting Author

Zoe Reed

Poster Authors

Jane Quinlan

MB BS

Oxford University Hospitals Trust, UK

Lead Author

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Zoe Reed

University of Oxford

Lead Author

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Samantha Ma MPharm

Oxford University Hospitals Trust

Lead Author

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Amy Hussey BSc

Oxford University Hospitals Trust

Lead Author

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Hanin Ramadan MBBS BSc

Oxford University Hospitals Trust

Lead Author

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Edward Flewitt

University of Oxford

Lead Author

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Nicole Hasler

University of Oxford

Lead Author

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Topics

  • Specific Pain Conditions/Pain in Specific Populations: Acute Pain and Nociceptive Pain

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