Zofran Dosage/Direction for Use

Dosage Regimen: Chemotherapy and Radiotherapy Induced Nausea and Vomiting (CINV and RINV): The emetogenic potential of cancer treatment varies according to the doses and combinations of chemotherapy and radiotherapy regimens used. The selection of dose regimen should be determined by the severity of the emetogenic challenge.
CINV and RINV in Adults: The recommended intravenous (IV) or intramuscular (IM) dose is 8 mg administered immediately before treatment. For highly emetogenic chemotherapy, a maximum initial ondansetron dose of 16 mg IV infused over 15 minutes may be used. A single IV dose greater than 16 mg should not be given. The efficacy in highly emetogenic chemotherapy may be enhanced by the addition of a single IV dose of dexamethasone sodium phosphate 20 mg, administered prior to chemotherapy. IV doses greater than 8 mg and up to a maximum of 16 mg must be diluted in 50 mL to 100 mL of 0.9% Sodium Chloride Injection or 5% Dextrose Injection before administration and infused over not less than 15 minutes (see INSTRUCTIONS FOR USE/HANDLING under CAUTIONS FOR USAGE). Doses of 8 mg or less, do not need to be diluted and may be administered as a slow IM or IV injection in not less than 30 seconds. The initial dose may be followed by 2 additional IV or IM doses of 8 mg 2 to 4 hours apart, or by a constant infusion of 1 mg/h for up to 24 hours. Oral treatment is recommended to protect against delayed or prolonged emesis after the first 24 hours.
CINV in Children and Adolescents (aged 6 months to 17 years): The dose for CINV can be calculated based on body surface area (BSA) or weight. In pediatric clinical studies, ondansetron (Zofran) was given by IV infusion diluted in 25 to 50 mL of saline or other compatible infusion fluid (see INSTRUCTIONS FOR USE/HANDLING under CAUTIONS FOR USAGE) and infused over not less than 15 minutes.
Dosing by BSA: Ondansetron (Zofran) should be administered immediately before chemotherapy as a single IV dose of 5 mg/m². The IV dose must not exceed 8 mg. Oral dosing can commence 12 hours later and may be continued for up to 5 days (Table 2). Adult doses must not be exceeded. (See Table 2.)

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Dosing by body weight: Ondansetron (Zofran) should be administered immediately before chemotherapy as a single IV dose of 0.15 mg/kg. The IV dose must not exceed 8 mg. On Day 1, two further IV doses may be given in 4-hourly intervals. Oral dosing can commence 12 hours late and may be continued for up to 5 days (Table 3). Adult doses must not be exceeded. (See Table 3.)

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CINV and RINV in Elderly: In patients 65 years of age or older, all IV doses should be diluted and infused over 15 minutes and, if repeated, given no less than 4 hours apart.
In patients 65 to 74 years of age, the initial IV dose of 8 mg or 16 mg, infused over 15 minutes, may be followed by 2 doses of 8 mg infused over 15 minutes and given no less than 4 hours apart. In patients 75 years of age or older, the initial IV dose should not exceed 8 mg infused over 15 minutes. The initial dose of 8 mg may be followed by 2 doses of 8 mg, infused over 15 minutes and given no less than 4 hours apart (see PHARMACOLOGY under ACTIONS).
Post-Operative Nausea and Vomiting (PONV): PONV in Adults: For prevention of post-operative nausea and vomiting, the recommended dose is a single dose of 4 mg by IM or slow IV injection administered at the induction of anaesthesia.
For treatment of established post-operative nausea and vomiting, a single dose of 4 mg given by IM or slow IV injection is recommended.
PONV in Children and Adolescents (aged 1 month to 17 years): For prevention and treatment of PONV in paediatric patients having surgery performed under general anaesthesia, ondansetron (Zofran) may be administered by slow IV injection (not less than 30 seconds) at a dose of 0.1 mg/kg up to a maximum of 4 mg either prior to, at or after induction of anesthesia, or after surgery.
PONV in Elderly: There is limited experience in the use of ondansetron (Zofran) in the prevention and treatment of post-operative nausea and vomiting in the elderly, however it is well tolerated in patients over 65 years receiving chemotherapy.
Special populations: Renal Impairment: No alteration of daily dosage or frequency of dosing, or route of administration are required.
Hepatic Impairment: Clearance of ondansetron is significantly reduced and serum half-life significantly prolonged in subjects with moderate or severe impairment of hepatic function. In such patients, a total daily dose of 8 mg IV or oral should not be exceeded.
Patients with Poor Sparteine/Debrisoquine Metabolism: The elimination half-life of ondansetron is not altered in subjects classified as poor metabolizers of sparteine and debrisoquine. Consequently, in such patients repeat dosing will give drug exposure levels no different from those of the general population. No alteration of daily dosage or frequency of dosing is required.