Efficacy Analysis of Capsaicin 8% Patch in Neuropathic Peripheral Pain Treatment

Abstract

Background/Aims: Several guidelines for neuropathic pain management and various effective drugs are available; however, neuropathic pain remains undertreated. This retrospective study aimed to evaluate the efficacy of topical capsaicin 8% in peripheral neuropathic pain in a routine clinical setting. Methods: Therapeutic efficacy was evaluated through pain intensity, using numerical pain rating scale at baseline and 7–14 days after each treatment, and using pain treatment area (PTA) assessed immediately before each treatment. Results: A total of 43 patients with either post-herpetic neuralgia or post-traumatic/post-surgical neuropathic pain were enrolled. The median percentage reduction in numerical pain rating scale score and in PTA was –40.0 (–50.0 to –33.3; 95% CI, bootstrap) and –35.1 (–50.9 to 3.4; 95% CI, bootstrap), respectively. Pain intensity and PTA were equally improved and reduced in both treated conditions. Conclusion: This study suggests that topical capsaicin 8% reduces peripheral neuropathic pain as well as treatment pain area.