Ondansetron Administration Guidelines for Chemotherapy-Induced Nausea and Vomiting

Dosing Duration by Treatment Context

For high emetogenic risk chemotherapy, the National Comprehensive Cancer Network recommends ondansetron typically given on day 1 only, with other antiemetics continued on days 2-4 1, 2
For moderate emetogenic risk chemotherapy, the National Comprehensive Cancer Network suggests ondansetron can be given on days 1-3 1, 3
For low emetogenic risk chemotherapy, the National Comprehensive Cancer Network recommends ondansetron as a single dose before chemotherapy, with additional doses only as needed for breakthrough symptoms 3, 4

For multi-day chemotherapy regimens, the American Society of Clinical Oncology recommends administering ondansetron daily during chemotherapy and for 2 days thereafter 2
For breakthrough nausea/vomiting, the American Society of Clinical Oncology suggests ondansetron can be used as rescue therapy, titrated up as needed to a maximum of 16 mg oral or IV daily 6, 7

For radiation therapy-induced nausea and vomiting, the National Comprehensive Cancer Network recommends ondansetron once or twice daily on days of radiation therapy and once daily on the day after each radiation treatment for high-risk radiation therapy 5, 6