Gabapentinoids for Neuropathic Pain After Spinal Cord Injury: An Updated Meta-Analysis of Randomized Controlled Trials.

Background and aim: Spinal cord injury (SCI) is a debilitating condition frequently associated with chronic symptoms such as central neuropathic pain (CNP) and its related complications. Gabapentinoids are often used in the treatment of post-SCI CNP; however, the optimal management of this condition is still unclear. This study aimed to assess the efficacy and safety of gabapentinoids compared with placebo in post-SCI patients affected by CNP.

Methods: We systematically searched PubMed, Embase, and Cochrane Library databases for randomized controlled trials (RCTs) comparing gabapentinoids (gabapentin, pregabalin, or mirogabalin) with placebo in post-SCI patients experiencing CNP. We calculated mean differences (MD) and risk ratios (RR) for continuous and dichotomous outcomes, respectively, with 95% confidence intervals (CI). Pain was measured on a 0 to 10 numerical rating scale.

Results: We included 5 RCTs comprising 682 patients. The mean age was 50.2 years, and 83.8% were male. When compared with placebo, patients treated with gabapentinoids experienced a significant decrease in average daily pain (MD -1.75; 95% CI: -3.23 to -0.28; p = 0.02) and pain-related sleep interference (MD -0.99; 95% CI: -1.38 to -0.60; p < 0.001). Additionally, there were higher proportions of individuals with pain intensity relief ≥ 50% (RR 2.19; 95% CI: 1.47 to 3.25; p < 0.001) and with at least some perceived improvement on the clinical global impression scale (RR 1.71; 95% CI: 1.34 to 2.18, p < 0.001) in the gabapentinoids group compared to the placebo group. However, treatment with gabapentinoids was associated with a significantly increased risk of blurred vision (RR 8.55; 95% CI: 1.53 to 47.7; p = 0.02), somnolence (RR 3.77; 95% CI: 2.44 to 5.84; p < 0.001), peripheral edema (RR 2.86; 95% CI: 1.37 to 5.99; p < 0.01), and dizziness (RR 2.83; 95% CI: 1.67 to 4.78; p < 0.001).

Conclusion: In this meta-analysis of RCTs evaluating patients with CNP following SCI, gabapentinoids were associated with significant improvements in pain and pain-related sleep interference compared with placebo. Nonetheless, gabapentinoids significantly increased the risk of adverse events.