An Open-Label Trial of the 5% Lidocaine Patches for the Treatment of Chronic Pain

ABSTRACT

BACKGROUND: There have been limited reports on the effectiveness of 5% lidocaine patches (L5Ps) for treating a few types of chronic pain. We utilized L5Ps for chronic pain patients with various diagnoses and who had incompletely responded to their current treatment regimen. This study aimed at describing the results of a retrospective review of an open-label L5P trial to assess L5Ps' effectiveness and safety for treating various chronic pain patients. METHODS: The chronic pain patients with pain lasting longer than 6-month duration were offered a 2-week L5P treatment trial. The patients were maintained on their other analgesic regimens. The treatment effect was measured according to the change from the baseline visual analog scale (VAS) to the week 2 VAS. After a 2-week trial, the patients were asked if they perceived pain improvement with L5Ps by using a four-item Pain Relief Scale (1 = a lot of relief, 2 = slight relief, 3 = no change, 4 = worse pain). RESULTS: In the combined patient population (n = 177), 2-week treatment with the L5Ps significantly improved the week 2 VAS (P = 0.000). Significant improvement in the VAS was reported by the chronic pain patients with postherpetic neuralgia, intercostal neuralgia, degenerative osteoarthritis at knee joint, and other maladies. A higher proportion of the chronic pain patients reported improving their pain by the L5Ps. Seven patients experienced mild or moderate patch-related adverse events. CONCLUSIONS: The L5P provided clinically meaningful pain relief in some refractory chronic pain patients without any severe adverse events.