RESUMO
Objective: In many medical institutions in Japan, 10% lidocaine gel is prepared as an in-hospital formulation to treat intractable neuropathic pain. Clinical studies have reported the short-term efficacy of topical lidocaine therapy for neuropathic pain, while there are few reports in real-world practice. To clarify the clinical usage and its usefulness, in this study, we investigated the duration of use, amount, effectiveness, and safety of 10% lidocaine gel.Design: We conducted a retrospective study investigating the actual usage of 10% lidocaine gel using electronic medical records.Methods: This study included 74 patients treated with 10% lidocaine gel in Kyoto University Hospital between July 2019 and January 2022. Information about disease (purpose of use), concomitant medications and other background information of the patients were collected. In addition, the duration of use, amount, adverse events, and discontinuation of 10% lidocaine gel were investigated. Effectiveness was determined by physician interviews and the pain visual analogue scale (VAS).Results: Ten percent lidocaine gel was used primarily to treat postherpetic neuralgia and, in some cases, other types of chronic pain for a median duration of use of 3.2 months (0.03-118.5). Pain relief was achieved in 73.3% of patients according to physician interviews, with a significant decrease in the VAS score. Although adverse events were observed in 12 patients (16.2%), including skin problems (12.2%), paralysis (4.1%), and somnolence (1.4%), eight patients continued to use 10% lidocaine gel after their occurrence. Three patients discontinued it due to adverse events, and their symptoms subsequently improved thereafter.Conclusion: The present results suggest that 10% lidocaine gel is effective and safe even when used for a long-time. Although this is a single-center study, it is the first systematic investigation of real-world usage of an in-hospital formulation of 10% lidocaine gel and is expected to assist clinical practice and drug development.