Patient-perceived symptomatic benefits of olanzapine treatment for nausea and vomiting in patients with advanced cancer who received palliative care through consultation teams: a multicenter prospective observational study

Purpose To examine the safety, effectiveness, and patient-perceived benefit of treatment with olanzapine for nausea and vomiting (N/V) in patients with advanced cancer. Methods We conducted a multicenter prospective observational study in a tertiary care setting (Trial registration number: UMIN000020493, date of registration: 2016/1/12). We measured the following: average nausea in the last 24 h using a Numeric Rating Scale (NRS: range 0–10) at baseline and day 2, patient-perceived treatment benefit (based on a 5-point verbal scale), and adverse events (AEs; using the Common Terminology Criteria for Adverse Events version 4). Results The 85 participants (45% men) had a mean age of 58.7±15.8 years. Major causes of N/V were opioids (44%) and chemotherapy (34%). All patients received a daily dose of olanzapine of 5 mg or less as first-line treatment ( N =35) or second- or later-line treatment ( N =50). Nausea NRS decreased from 6.1±2.2 to 1.8±2.0 (differences: −4.3, 95% CI −3.7 to −4.9, p