Effectiveness of Duloxetine for Postsurgical Chronic Neuropathic Disorders after Spine and Spinal Cord Surgery

Study Design: This is a retrospective observational study with an outpatient setting.Purpose: This study aimed to describe the effects of duloxetine (DLX) administration for postsurgical chronic neuropathic disorders(both pain and numbness) following spinal surgery in patients without depression.Overview of Literature: Although several reports indicated the potential of DLX to effectively treat postoperative symptoms as aperioperative intervention, there have been no reports of its positive effect on postsurgical chronic neuropathic disorders.Methods: A total of 24 patients with postsurgical chronic pain and/or numbness Numeric Rating Scale (NRS) scores of ≥4 wereenrolled. All patients underwent spine or spinal cord surgery at Keio University Hospital and received daily administration of DLX formore than 3 months. The mean postoperative period before the first administration of DLX was 35.5±57.0 months. DLX was administeredfor more than 3 months at a dose of 20, 40, or 60 mg/day, and the degree of pain and numbness was evaluated using the NRSbefore administration and 3 months after administration. Effectiveness was defined as more than a 2-point decrease in the NRS scorefollowing administration.Results: In terms of the type of symptoms, 15 patients experienced only numbness, eight experienced both pain and numbness, andone experienced only pain. Of the 24 patients, 19 achieved effective relief with DLX. DLX was effective for all patients with postsurgicalchronic pain (n=9), and it reduced postsurgical chronic numbness in 18 of 23 patients. No significant difference was observed inbackground spinal disorders. DLX was not effective for five patients who complained only of postsurgical chronic numbness.Conclusions: This study reports the effectiveness of DLX for postsurgical chronic neuropathic disorders. Although DLX reduced postsurgicalchronic pain (efficacy rate=100%) and numbness (78.3%)