Efficacy and Safety of Gabapentinoids in the Treatment of Carpal Tunnel Syndrome: A Systematic Review and Meta-Analysis.

Background: The off-label use of gabapentinoids for carpal tunnel syndrome (CTS) is increasing despite limited evidence of efficacy and known risks of adverse effects. This systematic review and meta-analysis aimed to synthesise the evidence of the benefits and harms of oral gabapentinoids in treating CTS. Methods: We searched Medline and Cochrane Central Register of Controlled Trials for randomised controlled trials (RCT). Based on the search results, we formed three comparisons assessing the effect of oral gabapentinoid interventions against (1) placebo (primary comparison), (2) open label no-treatment (with co-interventions in both arms) or (3) splinting. The primary outcome was symptom severity. The secondary outcomes were pain, function, clinical improvement, health-related quality of life, adverse effects and need for surgery. We adhered to the Cochrane and GRADE methodology throughout conducting this systematic review and meta-analysis. Results: Gabapentinoids probably do not improve CTS symptoms (moderate certainty) compared with placebo. The benefit was 0.08 points better (95% confidence interval [CI] 0.33 better to 0.17 worse; two studies, 286 randomised participants) expressed on the Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) Symptom Severity Scale (1-5 points, lower is better; minimal clinically important difference [MCID] 1.14 points) with gabapentinoids at 8 weeks. Secondary comparison to no treatment aligned with this finding. Gabapentinoids probably cause more fatigue (risk ratio [RR] 1.67 [95% CI 1.06-2.63]) and may cause more dizziness (RR 1.96 [95% CI 0.93-4.13]) compared to placebo. When compared to no-treatment at short term, gabapentinoids may provide minor benefits for pain but not for hand function. Conclusions: Current evidence does not support the use of oral gabapentinoids for CTS. There were no clinically important benefits in symptom relief when compared to placebo or no-treatment, and gabapentinoids caused adverse effects, particularly fatigue and maybe also dizziness. Level of Evidence: Level II (Therapeutic).