The efficacy of topical 8% capsaicin patches for the treatment of postsurgical neuropathic pain: a systematic review.

Objective: To investigate the benefits of topical 8% capsaicin patches for the decrease of postsurgical neuropathic pain level and area.

Methods: A systematic review with pooled analysis was conducted utilizing the PRISMA 2020 guidelines. Five commonly used databases were employed utilizing a search string made from MeSH terms and boolean operators. Retrieved articles were then subjected to title and abstract appraisal, followed by full-text appraisal by two independent reviewers and an adjudicator to break ties.

Results: A total of 127 articles were retrieved from five commonly used databases. Of the 127 articles, 20 were subjected to full-text appraisal, with 12 remaining for inclusion. Due to a heterogeneity greater than the 50% threshold provided by Cochrane, a random-effects pooled-analysis was conducted in lieu of meta-analysis. The random-effects pooled-analysis denotes an overall Cohen's d of 1.09 (95% CI: 0.58-1.56; p < 0.001). All studies that investigated neuropathic pain area denote a decrease in pain size, with some denoting a continued reduction with subsequent application.

Conclusion: Further larger randomized-controlled trials are required to strengthen the position of topical capsaicin patches in the physician's armamentarium.

Protocol registration: www.crd.york.ac.uk/prospero identifier is CRD42024542508.