Low-dose olanzapine, sedation and chemotherapy-induced nausea & vomiting: a prospective randomized controlled study

Lay abstract Methods to prevent chemotherapy-induced nausea and vomiting (CINV) are often not sufficient for patients. Olanzapine, along with other similar drugs (antiemetics), improved control but is often sedating. In this study, a lower dose of olanzapine was compared with the conventional dose. Patients on cancer chemotherapy, which has high occurrence of nausea and vomiting, were given either the low dose or the conventional dose of olanzapine for 3 days, in addition to some other antiemetic agents. Control of nausea and vomiting was reasonably achieved with both doses of olanzapine. The lower dose was significantly less sedating. There were no serious side effects with either doses. Aims: Comparison of efficacy, safety and sedation between two doses of olanzapine in the control of chemotherapy-induced nausea and vomiting (CINV). Patients & methods: A prospective, randomized, double-blind, controlled study was conducted, enrolling 68 patients receiving a single-day cycle of high and moderately emetogenic chemotherapy. Patients received either of olanzapine 5 mg or 10 mg from day 1 through 3 in addition to ondansetron and dexamethasone. Control of CINV, nausea, sedation, quality of life (QoL) and adverse events were compared. Results: Nausea, emesis control and improvement of QoL were similar in both groups. Sedation severity was 133% higher with 10 mg olanzapine. Conclusions: Lower dose olanzapine is effective to control CINV with significantly reduced sedation.