Recommended doses of opioid analgesics not linked with clinically meaningful relief for low back pain
Results from this study indicated opioid analgesics provided short-term relief for patients with chronic low back pain; however, this benefit may not be clinically significant with regard to guideline-recommended doses.
Two independent researchers collected data from 20 placebo-controlled randomized clinical trials that assessed opioid analgesics for low back pain. Investigators used a random effects model with strength evidence determined with the grading of recommendations assessment, development and evaluation.
Pain, as the primary outcome, was measured with the VAS and the numerical rating scale. Investigators also measured disability with Oswestry Disability Index and the Roland-Morris Disability questionnaire scores. Outcomes for pain and disability were converted to a 100-point scale and effects greater than 20 points were considered clinically important. Pain relief outcomes were categorized as short-term (fewer than 3 months), intermediate-term (3 months to 11 months) and long-term (12 months or more).
Results showed 13 of the 20 trials assessed short-term effects on chronic low back pain, and none were placebo-controlled trials of patients with acute low back pain. Investigators noted 50% of participants withdrew due to adverse events or lack of efficacy in half of the 13 trials. In the short-term, there was moderate-quality evidence that opioids reduced pain, with a mean difference of -10.1.
According to results from meta-regression, a 12-point greater pain relief was found for every 1 log unit increase in morphine-equivalent dose. Within the dose range evaluated (4 mg to 24 mg morphine-equivalents a day), pain relief was not clinically important. The enrichment study design did not have a significant effect on outcomes. ‒ by Monica Jaramillo
Disclosures: Shaheed reports no relevant financial disclosures. Please see the full study for a list of all others’ relevant financial disclosures.