A PROSPECTIVE OBSERVATIONAL STUDY TO COMPARE THE ANTIEMETIC EFFICACY AND SAFETY PROFILE OF TWO COMBINATIONS NAMELY ONDANSETRON-DEXAMETHASONE VERSUS PALONOSETRON-DEXAMETHASONE IN PROPHYLAXIS OF CISPLATIN INDUCED EMESIS

BACKGROUND Chemotherapy Induced Nausea and Vomiting (CINV) are among the most distressing symptoms for cancer patients and preventing this can lead to a better treatment outcome. Serotonin (5-HT3) receptor antagonists in combination with Dexamethasone remains the mainstay of treatment in chemotherapy-induced emesis. The purpose of this study is to compare the antiemetic efficacy and safety profile of Ondansetron, a first generation 5-HT3 receptor antagonist versus Palonosetron, a second generation 5-HT3 receptor antagonist, both in combination with Dexamethasone, in Cisplatin-induced emesis. This prospective observational study done over a period of 1 year included 120 adult patients scheduled for their first cycle of Cisplatin based chemotherapy regimen in a tertiary care centre of Kerala. These patients were divided into two groups of 60 patients each; group 1 received Ondansetron (8 mg) with Dexamethasone (8 mg) and group 2 received Palonosetron (0.25 mg) with Dexamethasone (8 mg) combinations both intravenously 30 minutes prior to Cisplatin administration. Efficacy of two regimens were compared in terms of complete response rate [ CR rate: no emesis and no significant nausea (nausea. 3 in nausea scale)] between two groups, in acute (0-24 hours) and delayed (>24-120 hours) phases of 1st and 2nd cycles of Cisplatin chemotherapy. Other parameters that were assessed include number of emetic episodes, frequency of nausea and treatment related adverse effects in both the groups. Nausea and vomiting was assessed using Multinational association of supportive care in cancer Antiemetic Tool (MAT). Results were analysed using Chi-square test. Analysis showed that Palonosetron-Dexamethasone combination was found to be more effective in preventing CINV in terms of CR rate and significantly higher responses were seen in delayed phases of both 1st (73.3% vs 50%, P value=0.009) and 2nd (78.3% vs 55%, P value=0.007) cycles of Cisplatin chemotherapy. When individual parameters were analysed, it was seen that percentage of patients with severe emesis (>2 emetic episodes) and those with severe nausea (>7 in nausea scale) were lower in Palonosetron group in all phases and significant difference were seen in delayed phases of both cycles. The incidence of treatment related adverse effects were mild and there was no significant difference between two groups.