Palonosetron versus ondansetron in chemotherapy induced nausea and vomitting

Introduction: Palonosetron is a longer acting -5 hydroxytryptamine- 3 (5-HT3) antagonist, used in preventing chemotherapy induced nausea and vomiting (CINV). It is licensed initially for the oncology patient group. It is given as an injection and acts over a five days period. Method: In our haematology setting we have conducted a small comparison study to compare the efficiency of Palonosetron and Ondansetron for haematology patients for preventing CINV. Stage 1 data was collected prospectively for Palonosetron over a year period. Second stage data was collected for efficiency of Ondansetron retrospectively, simply because Ondansetron is the main antisickness drug used in our centre. Patients who were in the Ondansetron group were selected randomly without any information given to ward nurses. The information was collected day 1- day 11 from the day chemotherapy started. There were 24 patients in each group. The data was compared in three different categories: complaints of nausea (severity), vomiting (how many episodes over 24 hour) and the requirement of additional anti-sickness. The patients in both groups received similar chemotherapy regimens. Patient demographic data and chemotherapy regimen are shown Table I. Result: Due to limited word count of this abstract, the outcome is evaluated on two sections instead of three: severity of nausea and frequency of vomiting. According to our study, patients who received Palonosetron suffered less from mild nausea. In this group a maximum of seven patients reported mild nausea where as 12 patients were reported similar episodes in the Ondansetron group. However, in the evaluation of vomiting, there was a trend in the Palonosetron group. Those patients receiving Palonosetron had their sickness/ vomiting peak on day 4. Palonosetron was given day 5, where the vomiting subsidised again. However 46% of patients who received Palonosetron have not vomited through out the chemo while 33% of Ondansetron group. Conclusion: Even though Palonosetron is manufactured for oncology patients, it is used for haematology patients. In our study Palonosetron was compared to Ondansetron. According to our study Palonosetron made a significant difference in preventing and reducing the CINV. Unfortunately the data was collected retrospectively for the Ondansetron group. Because of low number the outcome data could not be transferable to the whole patient group.