Topical capsaicin for the management of painful diabetic neuropathy: a narrative systematic review.

Aim: To investigate the potential benefit of topical capsaicin formulations. Materials & methods: A narrative systematic review was employed. Results: About 8% capsaicin patches were found to significantly reduce symptoms of diabetic peripheral neuropathy. Capsaicin was found to improve sleep quality (p = 0.02). Capsaicin patch exposure for 60 min showed significant reduction in symptoms (-32.8%). Capsaicin cream significantly reduced pain at weeks two and six (p = 0.003 and p = 0.03, respectively), but not at week eight in comparative studies. 0.025% capsaicin gel had an insignificant reduction in pain compared with placebo (p = 0.53), however 0.075% was found to be significant (p = 0.038). Capsaicin cream did not have superior improvement of pain as compared with clonidine gel (p = 0.931). The most common adverse events included application site discomfort, erythema and burning. Conclusion: Topical capsaicin treatments are a potentially beneficial peripherally acting medication. Further research is needed to determine the best means of ameliorating the side effects of treatments.