P43 Efficacy of antiemetics in patients receiving XELOX – A single-centre, prospective study

Background: XELOX (combination therapy of capecitabine and oxaliplatin) is known to cause nausea and vomiting, despite adequate administration of antiemetics. Furthermore, specific risk factors that may increase the risk of nausea and vomiting are unknown. Methods: This was a single-centre, prospective, cohort study. Patients were recruited on the day of chemotherapy, and were followed up after 5 days to assess nausea, vomiting, and use of antiemetics. Patients were assessed for nausea and vomiting control, as well as complete response, complete protection, and complete control of antiemetics. Use of delayed and breakthrough antiemetics were assessed, and multivariable logistic regression was done to evaluate risk factors that predisposed patients to nausea and vomiting despite use of antiemetics. Findings: 156 patients were included in this analysis. The median age was 60 years (IQR 55–65) with 88 (56.4%) men and 68 (43.6%) women. The proportion of patients achieving complete response, complete protection, and complete control within 24 hours after chemotherapy was 87.8%, 80.8%, and 62.8%, respectively. These proportions continued to decline throughout the follow-up period to 76.9%, 64.7%, and 48.7%, respectively, at the end of the 5 days. Patients who had fewer than three risk factors (odds ratio [OR] 3.13, p=0.006), who received oxaliplatin less than 100mg/m2 (OR 3.23, p=0.009), and who received capecitabine less than 1500mg/m2 (OR 5.00, p=0.04) were more likely to achieve complete response to antiemetics. Interpretation: This study showed that an unacceptably high proportion of patients receiving XELOX were unable to attain adequate control of nausea. Future research should focus on the optimisation of antiemetic therapy for patients receiving XELOX. Funding: National University of Singapore, Faculty of Science start-up grant. The authors declared no conflicts of interest.