Over the past decade an increasing reliance on opioids to treat pain has been associated with a rising epidemic of opioid misuse in the USA, that is now expanding globally. Lancet recently published three papers designed to address the role of inappropriate opioid prescribing after surgery as a major cause of the opioid crisis.
“From the mid-1990s, clinical guidelines and policies were created that aimed to eliminate pain, and clinicians were encouraged to increase opioid prescriptions. As a result, the use of prescription opioids more than doubled between 2001-2013 worldwide – from 3 billion to 7.3 billion daily doses per year, and has been linked to increases in misuse and abuse in some countries – like the US, Canada, Australia and the UK,” said Lancet series author Dr Brian Bateman, Brigham and Women’s Hospital, USA.
According to Lancet, acute postoperative pain develops into chronic pain in 10% of patients. This is increasingly being recognized, not only for the public health problem it represents, but also because previous approaches to manage this have contributed substantially to the opioid epidemic.
It typically begins as acute postoperative pain that is difficult to control, and develops into a persistent pain 
condition with features that are unresponsive to opioids. In response to this pain, clinicians often prescribe higher levels of opioids, but this can lead to tolerance and opioid-induced hyperalgesia (a counter-intuitive increase in pain in line with increased opioid consumption), creating a cycle of increased pain and increased opioid use where pain remains poorly managed.
“There are many ways to treat post-operative pain, and it has always struck me as sad that we don’t use more of them,” said Robert Twillman, PhD, former executive director of the Academy of Integrative Pain Management. “Yes, opioids work relatively well for post-operative pain, but they may be more risky than other treatments, and we have an ethical obligation to minimize that risk by using a variety of treatments that may reduce opioid requirements. Identifying how much opioid medication is needed for various surgeries is relatively easy, but I think we need to spend more time focusing on what we can do to eliminate the need for opioids, or at least reduce it substantially,” he said.
As well as often being ineffective at treating chronic pain, opioid prescriptions for pain after surgery have been linked to prescription opioid misuse and diversion, the development of opioid use disorder, and opioid overdose. Storing excess opioid pills in the home is an important source of diversion, and in one study 61% of surgery patients had surplus medication with 91% keeping leftover pills at home.
“Providing opioids for surgical patients presents a particularly challenging problem requiring clinicians to balance managing acute pain, and minimising the risks of persistent opioid use after surgery,” says series lead Professor Paul Myles, Monash University, Australia. “Over the past decade there has been an increasing reliance on strong opioids to treat acute and chronic pain, which has been associated with a rising epidemic of prescription opioid misuse, abuse, and overdose-related deaths. To reduce the increased risk of opioid misuse for surgery patients, we call for a comprehensive approach to reduce opioid prescriptions, increase use of alternative medications, reduce leftover opioids in the home, and educate patients and clinicians about the risks and benefits of opioids.”
There are also marked international differences in opioid prescribing after surgery. Data comparing one US and one Dutch hospital found that 77% of patients undergoing hip fracture repair in the US hospital received opioids, whereas none did in the Netherlands hospital, and 82% of US patients received opioids after ankle fracture repair compared with 6% of Dutch patients. Despite these differences, patients in each of these countries show similar levels of satisfaction with pain management.
A US study of more than 155,000 patients having one of four low-risk surgeries (carpal tunnel repair, knee arthroscopy, keyhole surgery for gallbladder removal, or keyhole surgery for inguinal hernia repair) found that opioid prescriptions for each increased from 2004-2012, and that the average daily dose of opioid prescribed for post-surgical pain also increased by 13% (30 milligrams of morphine equivalent [MME]) across all procedures on average, with increases ranging from 8% (17 MMEs) for patients undergoing inguinal hernia repair to 18% (45 MMEs) for patients undergoing knee arthroscopy (see Figure in paper 2).
“Better understanding of the effects of opioids at neurobiological, clinical, and societal levels is required to improve future patient care,” says series author Professor Lesley Colvin, University of Dundee, UK. “There are research gaps that must be addressed to improve the current opioid situation. Firstly, we must better understand opioid tolerance and opioid-induced hyperalgesia to develop pain relief treatments that work in these conditions. We also need large population-based studies to help better understand the link between opioid use during surgery and chronic pain, and we need to understand what predisposes some people to opioid misuse so that we can provide alternative pain relief during surgery for these patients. These recommendations affect many areas of the opioid crisis and could benefit to the wider crisis too.”
The authors of this series are calling for clinical guidelines and policies to give consensus for prescribing opioids after surgery that offer clinicians default and maximum prescription levels. For example, there is currently no guide on how long surgical patients should remain on opioids. To counter this, in the USA, a study devised prescribing recommendations for various surgeries (based on patient surveys and prescription refills data) – recommending postoperative opioids for 4-9 days for general surgery procedures, 4-13 days for women’s health procedures, and 6-15 days for musculoskeletal procedures. In addition, a study that adapted the default number of opioid pills prescribed from 30 to 12 showed marked decreases in the number of pills given after 10 common surgical procedures.
Conclusion/ The authors call for a comprehensive approach to reduce these risks, including specialist transitional pain clinics, opioid disposal options for patients (such as secure medication disposal boxes and drug take-back events) to help reduce home-stored opioids and the risk of diversion, and options for non-opioid and opioid-sparing pain relief. More research is also needed to help effectively manage opioid tolerance and opioid-induced hyperalgesia.
