A systematic review ¹ comparing 5-HT3 receptor antagonists to conventional anti-emetics in the prophylaxis of acute chemotherapy-induced vomiting included 30 RCTs. 5-HT3 antagonists reduced the risk of acute vomiting compared to conventional anti-emetics both with cisplatin treatments (OR 0.60, 95% CI 0.51 to 0.70; 15 studies) and with moderately emetogenic treatments (OR 0.47, 95% CI 0.39 to 0.58; 11 studies). The risk of acute vomiting seemed to be further reduced when 5-HT3 antagonists were combined with dexamethasone.

Another systematic review and network meta-analysis ² on 5-HT3 receptor antagonists (dolasetron, granisetron, ondansetron, palonosetron, tropisetron) for patients undergoing chemotherapy included 299 studies with a total of 58,412 subjects.

In the network meta-analysis, all 5-HT3 receptor antagonists were effective for reducing risk of nausea (44 studies, n=11,664, 12 treatments), vomiting (63 studies, n=15,460, 12 treatments), and chemotherapy-induced nausea or vomiting (27 studies, n=10,924, 9 treatments) compared to placebo. All treatments decreased the risk of severe vomiting (10 studies, n=917), but only ondansetron and ramosetron were significantly superior to placebo. According to the rank-heat plot, palonosetron + steroid was most likely the safest and most effective treatment. Across the effectiveness outcomes, the following treatments ranked as most superior on 3 effectiveness outcomes during the first 24 h after chemotherapy for adults: ondansetron + steroid, palonosetron + steroid, granisetron + steroid, and ramosetron + steroid.