Should Olanzapine be Advocated Over Conventional Anti-Emetics for the Prevention of Chemotherapy-Induced Nausea and Vomiting? An Updated Meta-Analysis of Randomized Control Trials

Abstract

Objective: The aim of this study is to synthesize the evidence about the efficacy of Olanzapine for the prevention of CINV. Methods: A computer literature search of PubMed, EBSCO, Ovid, and Cochrane CENTRAL databases has been conducted. Studies were screened for eligibility and data were extracted. The proportion of patients with complete response (CR) and those with no nausea were pooled as risk ratio (RR) in a fixed effect model meta-analysis using Review Manager Version 5.3 for windows. Results: Nine randomized controlled trials (n=1572) were pooled in the final analysis. In all studies, olanzapine was given as 10 mg PO. Olanzapine was superior to active control in terms of CR rate in acute phase (RR 1.12, 95% CI [1.02, 1.22], p=0.01]), delayed phase (RR 1.31, 95% CI [[1.10, 1.56], p=0.002), and overall phase (RR 1.30, 95% CI [1.09, 1.55], p=0.004). Rates of no nausea were significantly higher in olanzapine 10 mg group compared to active control group in acute phase (RR 1.20, 95% CI [1.04, 1.38], p=0.01), delayed phase (RR 1.72, 95% CI [1.42, 2.08], p<0.00001), and overall phase (RR 1.57, 95% CI [1.39, 1.77], p <0.00001). The incidence of adverse events was similar in olanzapine and control groups, with the most frequently reported treatment-related emergent adverse events being fatigue, constipation, and headache. Conclusion: Olanzapine is a well-tolerated drug for cancer patients and has shown superiority against conventional antiemetics for the prevention of CINV.