Nausea and vomiting is one of the most common and distressing side effects of antineoplastic chemotherapy, which seriously affects patients’ quality of life and treatment compliance. Chemotherapy vomiting reactions are mainly divided into 3 categories: acute reactions, 24 hours after chemotherapy, concentrated in 1-6 hours after drug administration; delayed reactions, after 24 hours after chemotherapy, which can last 5-7 days; anticipatory reactions, conditioned emission, related to psychiatric factors, with an incidence of 24%-65%. Chemotherapeutic agents are available as intravenous and oral chemotherapeutic agents, and the degree to which each agent causes emesis varies. The risk of emesis with chemotherapeutic agents is divided into four categories: high risk (emesis frequency >90%), medium risk (30%-90%), low risk (10%-30%), and very low risk (<10%), and very low risk is generally observed without intervention. This article summarizes the antiemetic protocols for several categories of risk. Several abbreviations: day 1 (d1), days 2 and 3 (d2-3), once daily (qd), oral (PO), intravenous (IV), once or twice (bid), dexamethasone (DXM), NK1 receptor antagonist (- NK-1), 5-HT3 receptor antagonist (- 5-HT3) Intravenous high emetic risk E.g. cisplatin, dacarbazine, nitrogen mustard hydrochloride, streptozotocin etc. Start before chemotherapy (choose one of regimens A, B, C) Regimen A: - NK-1, DXM + - 5-HT3 - NK-1 + DXM (choose one of two) d1 aripitant 125 mg PO, d2-3 80 mg PO qd; d1 dexamethasone 12 mg PO/IV, d2-4 PO/IV 8 mg qd d1 fosaprepitant 150 mg IV; d2 dexamethasone 80 mg PO, d3-4 PO/IV 8 mg qd mg PO, d3-4 PO/IV 80 mg bid - 5-HT3 (choose one of four) d1 dolasetron 100 mg PO d1 granisetron 2 mg PO, or 1 mg PO twice, or 0.01 mg/kg (up to 1 mg) IV, or transdermal patch of 3.1 mg/24h 24-48 hours before first chemotherapy d1 ondansetron 16-24 mg PO or 8 ~16 mg IV d1 palonosetron 0.25 mg IV Regimen B: nedupitant-containing regimen d1 nedupitant 300 mg or palonosetron 0.5 mg PO d1 dexamethasone 12 mg PO/IV, d2-4 8 mg PO/IV qd Regimen C: olanzapine containing regimen d1-4 olanzapine 10 mg PO qd d1 palonosetron 0.25 mg + Dexamethasone 20 mg IV intravenous in emetic risk E.g., leucovorin, carboplatin, actinomycin D, erythromycin, irinotecan, melphalan, methotrexate, oxaliplatin, etc. Start before chemotherapy (choose one of regimen A, B, or C) Regimen A: - 5-HT, DXM ± - NK-1 - 5-HT3 + DXM d1 dexamethasone 12 mg PO/IV + (choose one of the following four) dolasetron 100 mg PO granisetron 2 mg PO, or 1 mg PO twice, or 0.01 mg/kg (up to 1 mg) IV, or 24 to 48 h transdermal patch 3.1 mg/24h ondansetron 16-24 mg PO or 8-16 mg IV palonosetron 0.25 mg IV (preferred) d2-3 (four options) dolasetron 100 mg PO qd granisetron 1-2 mg PO qd or 1 mg PO bid or 0.01 mg/kg (up to 1 mg) IV qd ondansetron 8 mg PO bid or 16 mg PO qd or 0.01 mg/kg (up to 1 mg) IV bid or 16 mg PO qd or 8 to 16 mg IV qd dexamethasone 8 mg PO/IV qd - 5-HT3 + DXM + - NK-1 d1: Aripitant 125 mg PO or fosaprepitant 150 mg IV + dexamethasone 12 mg PO/IV + (choose one of four below) dolasetron 100 mg PO granisetron 2 mg PO, or 1 mg PO twice IV, or 0.01 mg/kg (up to 1 mg) IV, or 24-48 h prior to first chemotherapy Transdermal patch 3.1 mg/24 h Ondansetron 16-24 mg PO or 816 mg IV Palonosetron 0.25 mg IV (preferred) d2-3 If d1 with aripitant, aripitant 80 mg PO qd ± dexamethasone 8 mg PO/IV qd If d1 with fosaprepitant, then ± dexamethasone 8 mg PO/IV qd Option B: with nedupitant d1 nedupitant 300 mg / palonosetron 0.5 mg PO + dexamethasone 12 mg PO/IV ± d2-4 8 mg PO/IV qd Option C: with olanzapine d1-3 olanzapine 10 mg PO qd d1 dexamethasone 20 mg + palonosetron 0.25 mg IV IV low emetic risk E.g., lenalidomide, docetaxel, etoposide, 5-FU, gemcitabine, mitomycin, paclitaxel, pemetrexed, etc. Start before chemotherapy and repeat daily for multiple consecutive days of chemotherapy Four options Dexamethasone 12 mg PO/IV every hour of the day Gastrofacial 10-40 mg PO/IV every 4/6 hours if necessary Endrin 10 mg PO/IV every 6 hours if necessary (up to 40 mg daily) -5-HT3 (three options): dolasetron 100 mg/d PO , granisetron 1 to 2 mg/d (total dose) PO, ondansetron 8 to 16 mg/d PO Oral high emetic risk Chemotherapy started before and continued for multiple days Selective - 5-HT3 (triple choice) Dolasetron 100 mg/d PO Granisetron 1~2 mg/d (total dose) PO Ondansetron 16~24 mg/d PO Oral medium, low risk of emesis Pre-existing nausea and vomiting, recommended if necessary Four options Gastrofacial 10 to 40 mg PO, repeated every 4/6 hours if necessary Endrin 10 mg PO, repeated every 6 hours if necessary (up to 40 mg daily) Haloperidol 1 to 2 mg PO, repeated every 4/6 hours if necessary - 5-HT3 (three options): dolasetron 100 mg/d PO, granisetron 1 to 2 mg/d (total dose) PO, ondansetron 8~16 mg/d PO