Efficacy of palonosetron (PAL) compared to other serotonin inhibitors (5-HT3R) in preventing chemotherapy-induced nausea and vomiting (CINV) in patients receiving moderately or highly emetogenic (MoHE) treatments: Systematic review and meta-analysis.

e20620 BACKGROUND: Chemotherapy-induced nausea and vomiting (CINV) are frequent side effects of cancer treatment, with negative effects on quality of life. CINV may be acute (occurring within 24 hours after the chemotherapy) or delayed (up to 7 days after it). There are currently five serotonin inhibitors (5-HT3R) available on the market. PAL has the longer half-life, but there are controversies regarding if a better control of CINV (particularly delayed) is obtained with it. This controversy is reflected in recommendations of practice guidelines.OBJECTIVE: To perform a systematic review and meta-analysis of all randomized controlled trials comparing a single intravenous dose of PAL 0,25mg with other 5-HT3R in patients receiving MoHE chemotherapy.METHODS: We searched several databases, including MEDLINE, EMBASE, LILACS, and CENTRAL. The primary endpoints were the incidence of acute and delayed nausea and vomiting. The side effects of each treatment were analyzed. A subgroup analysis on the impact of added corticosteroids was performed.The results of individual studies were pooled in a meta-analysis, using the RevMan 5.1 software. The results are expressed as Risk Ratio (RR) and the correspondent 95% Confidence Interval (CI).RESULTS: We included 4 studies, with 1,298 patients. PAL was compared to ondansetron, granisetron and dolasetron. Patients in PAL group had less nausea, either acute (RR=0.75; CI= 0.64 to 0.88; P = 0.0004) or delayed (RR= 0.73; CI= 0.66 to 0.82; P < 0.00001). They also had less acute vomiting (RR = 0.78; CI= 0.67 to 0.90; P = 0.0008) and delayed vomiting (RR= 0.75; CI= 0.67 to 0.84; P < 0.00001). There were no statistical differences in side effects like headache (RR = 0.83; P = 0.29), dizziness (RR = 0.40; P = 0.12), constipation (RR = 1.35; P = 0.30) or diarrhea (RR = 0.67; P = 0.44). Patients receiving PAL presented less nausea and vomiting regardless of the use of corticoids. There was no statistical heterogeneity in the analises.CONCLUSIONS: PAL was more effective than the other 5-HT3R in preventing acute and delayed CINV in patients receiving MoHE treatments, regardless of the use of concomitant corticosteroids. [Table: see text].