INTRODUCTION: In Japan, both gabapentinoids and the Japanese traditional herbal medicine goshajinkigan (GJG) are used to manage chemotherapy-induced peripheral neuropathy (CIPN)
however, evidence for their effectiveness is inconclusive. Patients with CIPN experience reduced quality of life and often undergo reductions in dose or discontinuation of chemotherapy. Therefore, this retrospective cohort study used a real-world database to examine the efficacy of gabapentinoids and GJG therapy for patients with CIPN by evaluating chemotherapy duration and dose. METHODS: Data from 145,384 patients diagnosed with CIPN while receiving platinum- or taxane-based chemotherapy between April 1, 2008 and March 31, 2022 were stratified by CIPN treatment: simultaneous gabapentinoid (mirogabalin or pregabalin) plus GJG (prescription dates overlap)
non-simultaneous gabapentinoid plus GJG (prescription dates do not overlap)
gabapentinoid alone
GJG alone
and neither gabapentinoids nor GJG. Duration and dose of chemotherapy were the primary outcomes. RESULTS: Treatment with either a gabapentinoid or GJG alone was associated with longer duration and higher doses of chemotherapy versus neither gabapentinoids nor GJG in patients treated with carboplatin, cisplatin, or paclitaxel. Combined gabapentinoid plus GJG treatment elicited further longer duration and higher doses of chemotherapy versus gabapentinoid alone or GJG alone in patients treated with carboplatin, oxaliplatin, cisplatin, paclitaxel, or docetaxel. When stratified by cancer type, similar trends were observed regarding combination gabapentinoid plus GJG treatment among patients with colorectal cancer treated with oxaliplatin and patients with gastric, lung, or breast cancer treated with paclitaxel. CONCLUSION: Combination treatment with gabapentinoid plus GJG might prevent reductions in dose or discontinuation of chemotherapy, and might be effective for the treatment of CIPN.