A new North American study has found over-the-counter medications are just as effective as opioids for patient pain management following carpal tunnel surgery.
The study, published in the American Society of Plastic Surgeons, may provide clinicians and patients a level of confidence that over-the-counter pain medicines like ibuprofen or acetaminophen are not inferior to prescription opioids, said Western professor Joy MacDermid, a researcher at Western’s Bone and Joint Institute, the Dr. James Roth Chair in Musculoskeletal Measurement and Knowledge Translation and Canada Research Chair in Musculoskeletal Health Outcomes and Knowledge Translation.
The study involved 347 patients enrolled across five centres in Canada and the U.S., including 92 patients from The Hand and Upper Limb Centre at St Joseph’s Health Centre. The participants had all undergone carpal tunnel release procedure and were not previously taking daily opioid pain medication prior to surgery. Using the numeric pain rating scale (0 to 10) and the six-item pain interference scale, the participants’ pain scores were measured at multiple times per day for seven days following the surgery.
The researchers found no significant differences between opioid and over-the-counter in terms of the numeric pain rating scale scores, pain interference scores, number of doses of medication, or patient satisfaction. The highest recorded difference between the opioid and the over-the-counter groups was on the night of the surgery, when patients taking opioids had 0.9/10 points worse pain than those taking over-the-counter medication. To be clinically significant, there would have to be at least a two-point difference between the groups, but it was still a surprising outcome for the research team.
“Not only were (over-the-counter medicines) not inferior… but the direction of the difference was actually that the patients taking the opioids actually had a little bit worse pain score on the first night after surgery,” said MacDermid, who was a co-author of the study. “This makes us even more confident that the over-the counter pain relief medication was not inferior.”
Led by Dr. Donald Lalonde, professor in the Department of Plastic Surgery at Dalhousie University who practices in Saint John, N.B., this randomized, international study included researchers from Western University; University of Michigan Health System; Virginia Tech Carilion School of Medicine; Sanford School of Medicine at the University of South Dakota; and McGill University.
“Patients rely on their surgeon to tell them what kind of pain medication they need after surgery. So now surgeons can say, ‘We have a large clinical trial that shows that your pain relief is going to be good with over-the-counter medication,’” MacDermid said. She noted this advice applies to patients not currently taking opioids.
As the opioid crisis continues to be an important public health issue, particularly in North America, this study offers clinicians the evidence to make a case for prescribing over-the-counter medication over opioids for pain management in some post-surgery situations. In Canada, deaths from opioid toxicity rose 72 per cent, from 3,668 to 6,306, between 2019 and 2020, and 3,515 opioid-related deaths occurred just in the first six months of 2021, according to data from the Public Health Agency of Canada. In the U.S., 583,000 have died from opioid overdoses since 1999, according to the U.S. Centers for Disease Control and Prevention.
“The use of opioids in health care is much more prevalent in Canada and the United States than it is in other countries,” said MacDermid. “We know that there are adverse outcomes around opioids, and there is concern that a certain percentage of people – about five to 10 per cent – who’ve never taken opioids before and get them as part of pain management for any procedure… are then going to become persistent users, even though the opioids are no longer medically necessary six months or a year later.”
There is also the issue of misdirection, where opioids prescribed to a patient end up being taken by another person – through various ways, like theft or a family member using them inappropriately – which could lead to adverse events. Short or long-term use of opioids can also lead to addiction.
Public awareness on the dangers of opioids has increased in recent years, and studies like this can help inform pain management decisions, said MacDermid. In fact, the high-profile coverage of the opioid crisis seemed to be gaining traction among patients, she added.
“At one point, we wanted to do another study comparing opioids to other medications for people who had a broken hand bone, and we found a lot of patients no longer want to even participate in those studies because they’re so aware of the potential risk of opioids. Physicians who used to routinely give out opioids after injury, because they thought this was routine management, are now starting to change their practices, and trying to give lower-level medications like over-the-counter ones,” MacDermid said.
Increasing the evidence that limits the use of opioids in certain situations is one way to help address the opioid crisis. But, MacDermid said, things must be considered on a case-by case basis.
“We’re starting to see more studies like this and there had been a couple of studies prior to this that looked at this particular (carpal tunnel) operation. And it’s a good target because it isn’t a big operation,” she explained. “You don’t want to start with the biggest procedure; you want to start with the small ones and then keep working your way up to see at what level, if any, would opioids be necessary.”