A prospective randomized controlled clinical trial investigating the efficacy of low-dose olanzapine in preventing nausea and vomiting associated with oxaliplatin-based and irinotecan-based chemotherapy

Abstract Objective The aim of this study is to assess the clinical efficacy of a 5 mg dosage of olanzapine in preventing chemotherapy-induced nausea and vomiting (CINV) associated with moderately emetogenic chemotherapy (MEC) among female patients diagnosed with gastrointestinal tract tumors. Methods Patients undergoing the oxaliplatin/irinotecan chemotherapy regimen were enrolled in this prospective controlled study. The olanzapine group received a 5 mg dosage of olanzapine along with palonosetron and dexamethasone, while the control group received a standard two-combination regimen consisting of dexamethasone and palonosetron. The primary endpoints included the total protection (TP) rates for the entire age group and the subgroup aged 60 years and above. Secondary endpoints encompassed the total protection rates during the acute and delayed phases within the two age brackets, as well as the total control (TC) rates and complete remission (CR) rates across all three phases (total, acute, and delayed). Additionally, the study involved the assessment of quality of life and the collection of adverse events associated with the interventions. Results 1) Regarding the primary endpoint, the total phase TP rates within both the entire age group and the age group exceeding 60 years demonstrated superiority in the olanzapine group when compared to the control group (66.7% vs 37.25%, P = 0.003; 68.8% vs 44.4%, P = 0.044). 2) In terms of secondary endpoints, the olanzapine group exhibited superior acute phase TP rates in both age brackets when compared to the control group ( P 0.05). Furthermore, the quality of life in the olanzapine group surpassed that of the control group for both age brackets ( P < 0.05), characterized by enhanced appetite and a higher incidence of drowsiness in the patients treated with olanzapine when compared to those in the control group ( P < 0.05). Conclusion Olanzapine can enhance CINV induced by MEC regimen in female patients across all age groups, including the elderly, and therefore improve the quality of life for these patients. Clinical Trial Registration: https://www.chictr.org.cn/index.html , identifier: ChiCTR20000368269, 25/08/2020.