[Reduction of chronic pain for non-postherpetic peripheral neuropathies after topical treatment with a lidocaine patch]

Abstract

Introduction: To clarify whether the therapeutic indication for a lidocaine patch to treat postherpetic neuralgia can be extended to include other focal peripheral neuropathic pain syndromes, we performed a subgroup analysis of a placebo-controlled, double-blind randomized study.

Methods: The study included 16 patients with focal peripheral painful neuropathies of non-herpetic origin, pain intensity > or =40 mm (VAS), and a stable pain medication. The patients received either the lidocaine patch 5% for 1 week or a placebo patch for 12 h daily according to a crossover design. Persistent pain, mechanical allodynia, and adverse events were assessed daily by the patients. Additionally, the pain perception test, the list of physical complaints, the depression test, and the health-related quality of life (SF-36) were used. Of the enrolled patients, 12 were statistically analyzed.

Results: Persistent pain was reduced by the lidocaine patch almost significantly and allodynia was reduced significantly in comparison to the placebo patch. Scores for physical complaints improved significantly with the lidocaine patch. Only mild focal skin irritations occurred.

Conclusions: As an adjuvant medication, the lidocaine patch is effective and safe for reducing chronic pain and physical complaints in focal non-herpetic neuropathies.