Gabapentinoids are effective in decreasing neuropathic pain and other secondary outcomes after spinal cord injury: a meta-analysis.

OBJECTIVE: To examine the effectiveness of gabapentin and pregabalin in diminishing neuropathic pain and other secondary conditions in individuals with spinal cord injury (SCI). DATA SOURCES: A systematic search was conducted using multiple databases for relevant articles published from 1980 to June 2013. STUDY SELECTION: Controlled and uncontrolled trials involving gabapentin and pregabalin for treatment of neuropathic pain, with ≥3 subjects and ≥50% of study population with SCI, were included. DATA EXTRACTION: Two independent reviewers selected studies based on inclusion criteria and then extracted data. Pooled analysis using Cohen's d to calculate standardized mean difference (SMD), SE, and 95% confidence interval (CI) for primary (pain) and secondary outcomes (anxiety, depression, sleep interference) was conducted. DATA SYNTHESIS: Eight studies met inclusion criteria. There was a significant reduction in the intensity of neuropathic pain at <3 months (SMD=.96±.11; 95% CI, .74-1.19; P<.001) and between 3 and 6 months (SMD=2.80±.18; 95% CI, 2.44-3.16; P<.001). A subanalysis found a significant decrease in pain with gabapentin (SMD=1.20±.16; 95% CI, .88-1.52; P<.001) and with pregabalin (SMD=1.71±.13; 95% CI, 1.458-1.965; P<.001). A significant reduction in other SCI secondary conditions, including sleep interference (SMD=1.46±.12; 95% CI, 1.22-1.71; P<.001), anxiety (SMD=1.05±.12; 95% CI, .81-1.29; P<.001), and depression (SMD=1.22±.13; 95% CI, .967-1.481; P<.001) symptoms, was shown. A significantly higher risk of dizziness (risk ratio [RR]=2.02, P=.02), edema (RR=6.140, P=.04), and somnolence (RR=1.75, P=.01) was observed. CONCLUSIONS: Gabapentin and pregabalin appear useful for treating pain and other secondary conditions after SCI. Effectiveness comparative to other analgesics has not been studied. Patients need to be monitored closely for side effects.