Impact of Olanzapine on Refractory Chemotherapy-Induced Nausea and Vomiting: a Retrospective Study

Abstract

Specific Aims: To describe the outcomes of olanzapine in the treatment of refractory chemotherapy-induced nausea and vomiting (CINV). Methods: Data were collected regarding demographic information, chemotherapy regimen, CINV prophylaxis, rescue antiemetics, and olanzapine usage for subjects, age 18-79, who were admitted to the University of Arizona Medical Center for chemotherapy and received at least one dose of olanzapine for CINV between January 2008 and January 2012. The primary outcome measure was the number of rescue antiemetics required following the first dose of olanzapine (greater than 10 doses was considered treatment failure). Comparisons using chi square to determine if differences existed with respect to the level of chemotherapy emetogenicity and demographic information were conducted. Main Results: No statistical difference between chemotherapy regimens of high versus low-to-moderate emetogenicity was seen (P=0.79). However, 7 of 10 (70%) subjects receiving highly emetogenic chemotherapy achieved success and 15 of 23 (65%) subjects receiving low-to-moderately emetogenic chemotherapy achieved success. No statistical differences appeared when evaluating usage of 1 versus 2 or more prophylactic antiemetics (P=0.77), men versus women (P=0.08), and age over 50 versus 50 years or younger (P<0.99). Conclusion: This study demonstrated a trend towards greater emetic control with the addition of olanzapine in patients failing first-line antiemetic pharmacotherapy. Additionally, a trend towards greater emetic control was seen in women. The rates of success among all groups may suggest benefit to adding olanzapine to subjects experiencing refractory CINV. Due to the limited sample size and retrospective methodology of the study, the use of olanzapine in refractory CINV merits further research with large, prospective studies directly comparing addition of olanzapine to other appropriate antiemetics.