Nonsteroidal anti-inflammatory drugs (NSAIDs) might not be ideal analgesics for treating spinal-related pain, including neck and lower back pain, as indicated by results from a recent meta-analysis published in the Annals of Rheumatic Diseases.1
Although several clinical guidelines recommend using NSAIDs as a second-line therapy in patients with chronic or acute spinal-related pain, the meta-analysis found these agents do not “provide clinically important effects for spinal pain over placebo.”
“[We found] for every 6 patients treated with NSAIDs, rather than placebo, only 1 additional patient would benefit considering a between-group difference of 10 points for clinical importance in the short-term,” the investigators wrote. Given that paracetamol and opioids, the other analgesics recommended in clinical guidelines, have also been associated with suboptimal pain relief, these findings indicate “an urgent need to develop new analgesics for spinal pain,” they noted.
The meta-analysis included 35 randomized trials, with data from 6065 participants with spinal pain, including chronic or acute low back pain, sciatica, or neck pain. Patients in the studies were treated for a median duration of 7 days with oral, intravenous, intramuscular, or topical NSAIDs. The researchers used PRISMA recommendations, including GRADE, to assess the quality of the evidence in their included trials.
Collectively, the trials provided moderate-quality evidence that while NSAIDs reduce immediate- and short-term pain compared with placebo, the number of patients needed to treat to achieve a clinically significant pain reduction vs placebo was 5 in the immediate term (95% CI, 4 to 6) and 6 in the short-term (95% CI, 4 to 10). The effect on disability was found to be slightly smaller than for pain, with the magnitude of difference between the intervention groups not reaching the 10-point threshold for clinical importance in the immediate- (−8.1; 95% CI, −11.6 to −4.6) or short-term (−6.1; 95% CI, −9.5 to −2.8).
Subgroup analyses showed no difference in effect sizes when examining discontinued NSAIDs vs currently marketed drugs or NSAID delivery method (ie, oral vs intravenous/intramuscular vs topical). Effect size with COX-2 inhibitors was found to be larger than with nonselective NSAIDs, a finding that although statistically significant was determined to be of questionable clinical relevance.
Safety of NSAIDs for spinal pain was assessed in 21 studies and showed no significant difference in event rate between NSAIDs and placebo (relative risk [RR], 1.1; 95% CI, 1.0 to 1.2), but a significantly higher number of patients on NSAIDs reported gastrointestinal adverse effects (RR, 2.5; 95% CI, 1.2 to 5.2). “Overall, these results were based on high-quality evidence according to the GRADE evaluation,” the investigators wrote, but they noted that the data only included trials that used nonselective NSAIDs.
Summary and Clinical Applicability
“When [our findings] are taken together with those from recent reviews on paracetamol and opioids, it is now clear that the 3 most widely used and guideline-recommended medicines for spinal pain do not provide clinically important effects over placebo,” the investigators concluded. Subsequently, until more efficacious analgesics are developed for spinal pain, use of current analgesics, rescue medications, and other interventions might need to be better tailored to individual patients using a trial-and-error approach until clinical benefit is achieved.
- Trials investigating celecoxib, a commonly used COX-2 inhibitor, were not included in this analysis, but several trials of discontinued agents (eg, rofecoxib and valdecoxib) were.
- The findings reported are also limited to short follow-up times (about 1 week).
- Pooled estimates revealed substantial between-trial heterogeneity, and the data on neck pain was sparse and lacked information on whiplash, a common cause of neck pain.
- Machado GC, Maher CG, Ferreira PH, Day RO, Pinheiro MB, Ferreira ML. Non-steroidal anti-inflammatory drugs for spinal pain: a systematic review and meta-analysis [published online February 2, 2017]. Ann Rheum Dis. pii: annrheumdis-2016-210597. doi:10.1136/annrheumdis-2016-210597