2 DOSAGE AND ADMINISTRATION Prevention of Nausea and Vomiting Associated With Initial and Repeat Courses of Emetogenic Cancer Chemotherapy ( 2.1 ): Dilution of Ondansetron Injection in 50 mL of 5% Dextrose Injection or 0.9% Sodium Chloride Injection is required before administration to adult and pediatric patients. Adults and pediatric patients 6 months of age and older: The recommended dosage is 0.15 mg/kg per dose for 3 doses (maximum of 16 mg per dose), infused intravenously over 15 minutes. Administer the first dose 30 minutes before the start of chemotherapy and subsequent doses 4 and 8 hours after the first dose. Prevention of Postoperative Nausea and/or Vomiting ( 2.2 ): Dilution of Ondansetron Injection is not required before administration to adult and pediatric patients. See full prescribing information for the recommended dosage and administration instructions for adult and pediatric patients 1 month of age and older. Patients With Severe Hepatic Impairment ( 2.3 ): Do not exceed a total daily dose of 8 mg. 2.1 Prevention of Nausea and Vomiting Associated With Initial and Repeat Courses of Emetogenic Chemotherapy Important Preparation Instructions Dilution of Ondansetron Injection in 50 mL of 5% Dextrose Injection or 0.9% Sodium Chloride Injection is required before administration to adult and pediatric patients for the prevention of nausea and vomiting associated with emetogenic chemotherapy. For pediatric patients between 6 months and 1 year of age and/or 10 kg or less: Depending on the fluid needs of the patient, Ondansetron Injection may be diluted in 10 to 50 mL of 5% Dextrose Injection or 0.9% Sodium Chloride Injection. Occasionally, ondansetron precipitates at the stopper/vial interface in vials stored upright. Potency and safety are not affected. If a precipitate is observed, resolubilize by shaking the vial vigorously. Do not mix Ondansetron Injection with solutions for which physical and chemical compatibility has not been established. In particular, this applies to alkaline solutions as a precipitate may form. Inspect the diluted Ondansetron Injection solution for particulate matter and discoloration before administration; discard if present. Storage: After dilution, do not use beyond 24 hours. Although Ondansetron Injection is chemically and physically stable when diluted as recommended, sterile precautions should be observed because diluents generally do not contain preservative. Compatibility: Ondansetron Injection is compatible and stable at room temperature under normal lighting conditions for 48 hours after dilution with the following intravenous fluids: 0.9% Sodium Chloride Injection, 5% Dextrose Injection, 5% Dextrose and 0.9% Sodium Chloride Injection, 5% Dextrose and 0.45% Sodium Chloride Injection, and 3% Sodium Chloride Injection. Dosage and Administration The recommended dosage for adult and pediatric patients 6 months of age and older for prevention of nausea and vomiting associated with emetogenic chemotherapy is 0.15-mg/kg per dose for 3 doses (maximum of 16 mg per dose). Caution: Dilution of Ondansetron Injection is required in adult and pediatric patients prior to administration. Infuse intravenously over 15 minutes beginning 30 minutes before the start of emetogenic chemotherapy and then repeat 4 and 8 hours after the first dose. 2.2 Prevention of Postoperative Nausea and/or Vomiting Important Preparation Instructions Dilution of Ondansetron Injection is not required before administration to adult and pediatric patients. Inspect Ondansetron Injection visually for particulate matter and discoloration before administration; discard if present. Dosage and Administration The recommended dose and administration instructions for adult and pediatric patients 1 month of age and older for prevention of postoperative nausea and vomiting are shown in Table 1. Table 1. Recommended Dose and Administration of Ondansetron Injection for Prevention of Postoperative Nausea and/or Vomiting Population Recommended Single Dose Administration Instructions Timing of Administration Adults and pediatric patients older than 12 years of age 4 mg a May be administered intravenously or intramuscularly: Intravenously: infuse undiluted syringe contents (4 mg) over at least 30 seconds and preferably longer (over 2 to 5 minutes). Intramuscularly: inject undiluted syringe contents (4 mg) Administer immediately before induction of anesthesia, or postoperatively if the patient did not receive prophylactic antiemetics and experiences nausea and/or vomiting occurring within 2 hours after surgery b,c Pediatric patients 1 month to 12 years and more than 40 kg 4 mg Infuse intravenously over at least 30 seconds and preferably longer (over 2 to 5 minutes). Pediatric patients 1 month to 12 years and 40 kg or less 0.1 mg/kg Infuse intravenously over at least 30 seconds and preferably longer (over 2 to 5 minutes). a Few patients above 80 kg have been studied. b Administration of a second intravenous dose of 4 mg ondansetron postoperatively in adult patients who received a 4 mg prophylactic dose does not provide additional control of nausea and vomiting [see Clinical Studies (14.3)] . c For pediatric patients (1 month to 12 years) prevention of nausea and vomiting was only studied in patients who had not received prophylactic ondansetron. 2.3 Dosage Adjustment for Patients With Hepatic Impairment In patients with severe hepatic impairment (Child-Pugh score of 10 or greater), a single maximal daily dose of 8 mg infused over 15 minutes beginning 30 minutes before the start of the emetogenic chemotherapy is recommended. There is no experience beyond first-day administration of ondansetron in these patients [see Use in Specific Populations (8.6) ].