Author: Lizette Borreli
Long prescribed for managing acute pain management, opioid analgesics may only provide modest and short-lived relief for many conditions and no clear benefit for others.
Results of a large review of prior studies on opioids for acute pain, which evaluated systematic reviews covering more than 50 acute pain conditions in both children and adults, showed that opioids were slightly more effective than placebo for some conditions, such as acute abdominal pain and dental surgery, but offered little or no advantage for several others. In some cases, opioid use was also associated with an increased risk for adverse effects (AEs).
The findings suggest clinicians should carefully weigh the benefits and risks of opioids for acute pain before prescribing and consider safer alternatives, when possible, the investigators noted.
“Opioids are among the most commonly prescribed treatments for acute pain; however, our review found that they did not provide large or lasting pain relief compared with placebo for the vast majority of acute pain conditions,” study investigator Christina Abdel Shaheed, PhD, associate professor at the School of Public Health at The University of Sydney in Sydney, Australia, said in a statement.
“By showing that the benefits are generally small, short-lived, absent for many common conditions, and sometimes harmful, our research challenges the widely held belief that opioids are the most effective ‘go-to’ option for acute pain,” she added.
The study was published online on February 25 in Drugs.
Growing Concern
Opioids, including codeine, morphine, oxycodone, and tramadol, are frequently prescribed for acute pain related to injury, surgery, and other short-term medical conditions.
Despite widespread use, opioids have come under increasing scrutiny due to concerns about misuse, dependence, and overdose, raising questions about clinical value and appropriate prescribing practices.
Previous research has shown that opioids can be effective for severe pain, particularly in postoperative or trauma settings. However, evidence has suggested that opioids may have limited benefit for some common acute conditions.
For the current review, investigators examined systematic reviews and meta-analyses that compare opioid analgesics with placebo or no treatment for acute, noncancer pain.
The review included 59 systematic reviews of randomized clinical trials that evaluated opioids across more than 50 acute pain conditions, with acute pain defined as pain lasting less than 3 months.
These conditions included postoperative pain, musculoskeletal injuries, traumatic limb pain, abdominal pain, dental procedures, childbirth-related pain, and dermatologic conditions. The patient population represented both children and adults experiencing different types of acute pain.
Opioids were administered via oral, intravenous, and topical routes.
Daily opioid doses ranged from 0.2 to 180 morphine milligram equivalents per day. Pain outcomes were assessed at multiple timepoints: immediate (≤ 3 hours), short-term (> 3 to ≤ 6 hours), intermediate (> 6 to ≤ 48 hours), and long-term (> 48 hours).
Across included trials, immediate-term data represented 8407 participants in 86 trials, short-term data included 4998 participants in 42 trials, intermediate-term data included 7470 participants in 75 trials, and long-term data included 1002 participants in five trials.
The primary outcome was pain reduction, and secondary outcomes included AEs, disability, and quality of life.
Only Modest Benefit
Overall, the investigators found that opioid analgesics provided only modest benefits for many acute pain conditions.
High-certainty evidence showed morphine, oxycodone, tramadol, and papaveretum reduced acute abdominal pain at immediate-term follow-up (mean difference [MD], -18.4; 95% CI, -31.9 to -5.0). Opioids also reduced pain following dental surgery (MD, -19.5; 95% CI, -25.0 to -14.0) and myringotomy procedures (intravenous fentanyl; MD, -15.0; 95% CI, -19.6 to -10.4).
For acute musculoskeletal pain, oral opioids offered only very modest pain relief at intermediate-term follow-up (MD, -8.9; 95% CI, -13.5 to -4.3).
Overall, oral opioids provided only slightly better pain relief than placebo for acute musculoskeletal pain in the 6-48 hours after treatment began, Shaheed noted.
Moderate-certainty evidence showed opioids were ineffective for several conditions, including hysteroscopy-related pain, certain limb surgeries, and renal colic. There were no available clinical trial data for several scenarios, such as pain in newborns undergoing therapeutic hypothermia or chemotherapy-related mucositis in children.
Opioid use was also associated with an increased risk for AEs in some settings, including nausea and vomiting.
Compared with placebo, opioids increased the likelihood of AEs in acute musculoskeletal pain (risk difference, 0.1; 95% CI, 0.0-0.2), traumatic limb pain (risk ratio [RR], 3.0; 95% CI, 1.9-4.7), and some postoperative pain conditions (RR, 1.4; 95% CI, 1.2-1.6).
The investigators noted that harms data were frequently underreported. “Without comprehensive harms data, the evidence is unbalanced, failing to provide equal weight to benefits and harms, and generalizing from other conditions can either underestimate or overestimate effect sizes,” they wrote.
Additional study limitations included short-term follow-up in most trials, incomplete reporting of side effects, varied quality of the included reviews, gaps in evidence for some types of acute pain, and unclear details on opioid dosing.
Need for Judicious Use
The findings highlight the importance of judicious opioid prescribing for acute pain.
The investigators noted that effective pain management is essential for healing and recovery and that opioids can still play a role in clinical care when used judiciously. They emphasized that patients should be counseled about potential risks and that clinicians should prescribe opioids cautiously.
“It is important that patients are informed about the potential harms from opioids when prescribed them, and that doctors prescribe these medicines judiciously (lowest effective dose for the smallest amount of time) for acute pain,” co-first author Stephanie Mathieson, PhD, School of Public Health, The University of Sydney, said in a release.
The review also has implications beyond individual patient care. The investigators concluded that some opioid analgesics may not be safe or effective for certain acute pain conditions, a finding that could inform future updates to clinical guidelines. They added that additional high-quality clinical trials are needed to better define the benefits and harms of opioids for specific acute pain conditions.