Enrique Calderón, María Eloísa Calderón-Seoane, Rafael García-Hernández, Luis Miguel Torres

Chronic neuropathic pain and chronic complex regional pain syndrome (CRPS), in particular, are debilitating and difficult-to-treat conditions that have a strong impact on patient's quality of life. The aim of this study was to evaluate the effectiveness of 5% lidocaine-medicated plaster as add-on therapy in patients with chronic peripheral neuropathic pain conditions, including CRPS. This was a single-center, prospective, observational study set in a specialized pain unit of a tertiary hospital in Spain. A total of 56 patients with long-standing peripheral neuropathic pain, ten of them with CRPS, received 5% lidocaine-medicated plaster as add-on analgesic therapy for 6 months. After 6 months of treatment, a ≥50% reduction in pain intensity was attained by 75% of patients, as measured by numeric rating scale (NRS) for pain. The average NRS score was reduced by 61% (4.7 points), from a baseline mean score of 7.8 to an end point mean score of 3.1. Marked improvements were also observed in the CRPS group: six out of ten patients achieved a ≥50% reduction in NRS score, and the average NRS score for patients with CRPS was reduced by 51% (4.0 points), from a baseline mean score of 7.9 to an end point mean score of 3.9. The improvements in pain intensity were partially translated into a decrease in disability index and in anxiety levels. 5% Lidocaine-medicated plaster may be useful as add-on therapy for a number of peripheral neuropathic pain conditions, including CRPS.