Opioids and gabapentinoids for postoperative pain: Do we have a problem? 

The International Association for Study of Pain (IASP) define chronic post-surgical pain as “clinical discomfort lasting for more than three months post-surgery without other causes of pain.” To avoid this, post-operative pain should be managed effectively prior to discharge. Discussions should be held with the patient to discuss their existing comorbidities, risk factors and previous pain history, as well as the risks and benefits, including long term, of different types of analgesia. The prescribers should choose the most effective dose for the patient, to minimise pain but also reduce number of adverse effects.

A multimodal approach should be used in the management of post-operative pain, combining analgesics from different classes. Oral opioids should be used if postoperative pain is expected to be moderate to severe, and opioid sparing agents are used to reduce side effects, opioid consumption, and reliance. 

Gabapentinoids are used as part of the multimodal analgesic approach to managing post-operative pain. In some Trusts they are used to treat acute neuropathic pain as well as opioid sparing agents; however, evidence for use as an opioid sparing agent is weak. A systematic review into the enhanced recovery after surgery and opioid sparing strategies after discharge concluded that more specific research was needed before determining the efficacy of opioid-sparing agents post-operatively.  

The continued prescribing of opioids and gabapentinoids in primary care for post-operative pain has been recognised as an area of concern for public health

Gabapentinoids have a defined role in the management of multiple conditions, primarily neuropathic pain. However, when used for post-operative analgesia purposes – an unlicensed indication – they are not guaranteed to benefit each individual patient. Gabapentinoids are associated with euphoric effects and therefore have the potential for being abused. They were reclassified as Class C controlled substances (schedule 3 controlled drug) in 2019.

They also have significant central nervous system effects which can worsen when used concomitantly with other centrally acting drugs including opioids. Between 2017 and 2018, 1.5million people received and had dispensed one or more gabapentinoid prescriptions

The MHRA has produced prescribing alerts for co-prescribing opioids and gabapentinoids due to an increased risk of respiratory depression and neurological effects, including at-risk patient groups and considerations of dose reductions when prescribed more than one CNS depressant.

The continued prescribing of opioids and gabapentinoids in primary care for post-operative pain has been recognised as an area of concern for public health as it may contribute to opioid abuse and related harm in the UK. A review of opioid prescribing in primary care has shown that prescribers are issuing prescriptions for stronger opioid drugs to patients, more frequently. This is at its highest in more deprived regions, such as The North of England and East Midlands.

In secondary care opioids may be started as part of enhanced recovery programmes aimed at speeding recovery and discharge but a consequence of this is that patients may be discharged before analgesia can be reviewed, increasing the risk of patients not being stepped down to weak opioids such as codeine, or discontinued altogether before discharge. The persistent use in primary care may be linked to an increase in prescribing following initiation in hospital and a continuation in primary care, either due to patient requests or under instruction of the hospital discharge, although this is an area which may require further research. 

Guidelines from the Faculty of Pain Medicine have outlined steps for safe discharge on opioids for post-operative pain management. The post-operative recommendations include optimising pain relief with a clear pain management plan. To decrease the risk of long-term continuation patients should be reviewed for de-escalation prior to discharge and immediate-release opioids are preferred. On discharge patients should be counselled on safe self-administration, weaning and disposal of opioids. Local protocols for discharge prescriptions (TTOs) should be developed to reduce inappropriate prescribing; they should be prescribed for 5-7 days total and TTOs should include a discharge letter clearly stating the recommended dose, amount supplied and planned duration of use. Guidance should also be given regarding medicines review following discharge.

The opinions expressed in this article are those of the author. They do not purport to reflect the opinions or views of the UKCPA or its members. We encourage readers to follow links and references to primary research papers and guidance.

Competing interest statement: 

The author declares: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.


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