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.
Keywords: Chronic pain; complementary therapy; neuropathic pain; pharmacology; postoperative pain.
Capsaicin, a common substance that gives pepper plants their spice, can be used to help treat nerve pain when concentrated into an 8% patch. Eight percent capsaicin patches offer a non-pill-based alternative for pain relief, which may not be responding to other forms of treatment. When an individual undergoes surgery, they are often left with nerve pain around the location of the procedure or scar. Post-surgical nerve pain is often located in sensitive areas that are difficult to treat, and our results indicate that adequate treatment combining topical numbing medications followed by 8% capsaicin patches can provide significant and sustained relief (lasting up to a few months following the treatment). In addition to reducing the severity of post-surgical nerve pain, capsaicin can also shrink the overall size of the area of nerve pain. Although this treatment is newer compared to more commonly used medicines, it offers significant promise for helping relieve nerve pain in patients who have undergone various types of surgery across various parts of their bodies. Further studies are required to determine the exact amount of benefit this treatment can provide when compared to commonly used medications and therapies.