Combination of Mirogabalin and Duloxetine Attenuates Peripheral Neuropathy by Eribulin: A Novel Case Report

Chemotherapy-induced peripheral neuropathy (CIPN) is one of the most severe complications associated with chemotherapy for breast cancer. We encountered a case in which mirogabalin initially ameliorated, and additional duloxetine further attenuated eribulin-induced CIPN. Herein, we report its management. A 53-year-old woman received eribulin treatment as third-line chemotherapy for recurrent breast cancer. She experienced grade 2 CIPN with adjuvant docetaxel and cyclophosphamide treatment (worst numeric rating scale (NRS) 6/10 for numbness and 6/10 for pain) and had baseline grade 1 symptoms only in the hands (NRS 1/10 for each). CIPN in the hands and feet worsened to NRS 3/10 on day 1 of cycle 4. Mirogabalin (5 mg twice daily) was initiated, resulting in stable symptoms for approximately 6 weeks with grade 1 somnolence and heaviness of the head. The dosage was increased with careful attention to adverse effects to 22.5 mg per day, and the NRS was reduced from 5/10 to 3/10 for numbness and from 8/10 to 5/10 for pain. We administered duloxetine 20 mg with domperidone (10 mg three times a day) for further pain attenuation on day 1 of cycle 15, decreasing the NRS to 1/10 for numbness and 3/10 for pain. Duloxetine was increased due to CIPN degradation (NRS 3/10 and 5/10), resulting in a significant pain attenuation to 1/10. As the CIPN-attenuating mechanisms of mirogabalin and duloxetine are different, we consider that the additive and synergetic effects of this combination affected the results. Combination therapy with these drugs may be a promising strategy.