Are gabapentinoids safe and effective in treating patients with chronic low back pain?
The existing data on gabapentinoids for chronic low back pain are limited in number and quality. The amount of pain reduction is low to moderate, and the rate of adverse effects is high. The few studies that assessed function found no improvement. (Level of Evidence = 2a –)
These authors searched two databases and the Cochrane clinical trials register to identify randomized trials of gabapentinoids (gabapentin [Neurontin], pregabalin [Lyrica]) for treating adults with back pain lasting at least three months. Two authors independently assessed the inclusion of articles, and they resolved disagreements by consensus or through third-party adjudication. Ultimately, they included eight small studies with three different comparison treatments. Most of the studies had methodological quality issues, including selection bias and inadequate concealment of randomization. Three studies with 185 patients compared gabapentin with placebo, finding minimal improvement in pain. Three studies with 332 patients compared pregabalin with other analgesics, finding pregabalin was more effective in average pain response. The remaining studies, which assessed pregabalin as an adjunct to pain management, were heterogeneous, and the authors chose not to pool the data. The largest of these studies, however, found that adding pregabalin did not improve pain.
We have commented often on the inconsistent reporting of treatment harms in clinical trials, and these studies are no exception. However, the authors were able to pool data and estimate the number needed to treat to harm (NNTH) for several adverse effects: dizziness (NNTH = 7; 95% confidence interval [CI], 4 to 30), fatigue (NNTH = 8; 95% CI, 4 to 44), altered mentation (NNTH = 6; 95% CI, 4 to 15), and vision disturbance (NNTH = 6; 95% CI, 4 to 13). The studies generally did not report on functional outcomes.
Study design: Meta-analysis (randomized controlled trials)
Funding source: Government
Setting: Various (meta-analysis)
Reference: ShanthannaHGilronIRajarathinamMet alBenefits and safety of gabapentinoids in chronic low back pain: a systematic review and meta-analysis of randomized controlled trials. PLoS Med2017;14(8):e1002369.