Effect of duloxetine in Japanese patients with chemotherapy-induced peripheral neuropathy: a pilot randomized trial

Chemotherapy-induced peripheral neuropathy (CIPN) is difficult to manage. A phase III trial conducted in the United States demonstrated that duloxetine was effective for CIPN caused by taxane and platinum-based chemotherapy. No randomized trial of duloxetine for CIPN has been conducted in Japan. In this open-label, randomized, crossover study, eligible patients were randomized to Group A or Group B. Group A received duloxetine 20 mg/day orally for the first week and 40 mg/day for the next 3 weeks. Group B received vitamin B12 (VB12) 1.5 mg/day orally for 4 weeks. After a 2- to 4-week washout period, treatment was crossed over for another 4 weeks. The severity of numbness and pain was assessed using a visual analog scale (VAS). Thirty-four patients were enrolled. Obvious decreases in the mean VAS scores for numbness and pain were observed for the periods of duloxetine administration. Significant differences were observed between the duloxetine-first (Group A) and the VB12-first (Group B) groups with respect to numbness (p = 0.03) and pain (p = 0.04) at 4 weeks after administration. Fatigue was observed in six of the 34 participants (17.6 %). Our data suggests that duloxetine has a beneficial effect on CIPN caused by oxaliplatin, paclitaxel, vincristine, or bortezomib in Japanese patients.