Effectiveness of palonosetron versus granisetron in preventing chemotherapy-induced nausea and vomiting: a systematic review and meta-analysis.

PURPOSE: Chemotherapy-induced nausea and vomiting (CINV) commonly occurs after chemotherapy, adversely affecting patients' quality of life. Recently, studies have shown inconsistent antiemetic effects of two common 5-hydroxytryptamine 3 receptor antagonists, namely, palonosetron and granisetron. Therefore, we conducted a meta-analysis to evaluate the effectiveness of palonosetron versus granisetron in preventing CINV. METHODS: Relevant studies were obtained from PubMed, Embase, and Cochrane databases. The primary outcome was the complete response (CR) rate. Secondary outcomes were headache and constipation events. RESULTS: In total, 12 randomized controlled trials and five retrospective studies were reviewed. Palonosetron was consistently statistically superior to granisetron in all phases in terms of the CR rate (acute phases: odds ratio [OR] = 1.28, 95% confidence interval [CI] = 1.06-1.54; delayed phases: OR = 1.38, 95% CI = 1.13-1.69; and overall phases: OR = 1.37, 95% CI = 1.17-1.60). Moreover, a non-significant difference was found between the two groups in terms of the headache event, but the occurrence of the constipation event was lower in the granisetron group than in the palonosetron group. CONCLUSION: Palonosetron showed a higher protective efficacy in all phases of CINV prevention, especially in delayed phases, and no relatively severe adverse effects were observed.