Zetron Dosage/Direction for Use

Chemotherapy and radiotherapy induced nausea and vomiting: Adults: The route of administration and dose of ZETRON should be flexible in the range of 8-32 mg a day.
Emetogenic chemotherapy and radiotherapy: 8 mg should be administered as a slow intravenous injection immediately before treatment or 8 mg orally 1-2 hours before treatment, either regimen is followed by 8 mg orally every 12 hours for up to 5 days after a course of treatment to protect against delayed emesis.
Highly emetogenic chemotherapy: Intravenous regimen is recommended. The following dose schedules appear to be equally effective: 1. A single dose of 8 mg by slow intravenous injection immediately before chemotherapy.
2. A dose of 8 mg by slow intravenous injection immediately before chemotherapy, followed by two further intravenous doses of 8 mg 2-4 hours apart.
3. A dose of 8 mg by slow intravenous injection immediately before chemotherapy, followed by a continuous infusion rate of 1 mg/hour for 24 hours.
4. A single dose of 32 mg diluted in 50-100 ml of saline or other compatible infusion fluids (as indicated) and infused over not less than 15 minutes immediately before chemotherapy.
The selection of dose regimen should be determined by the severity of the emetogenic challenge.
The efficacy of Ondansetron will be enhanced by the addition of a single intravenous dose of dexamethasone sodium phosphate 20 mg administered prior to chemotherapy.
To protect against delayed emesis after the first 24 hours, ZETRON should be continued orally, 8 mg twice daily for up to 5 days after a course of treatment.
Children: Dose of 5 mg/m² body-surface intravenously immediately before chemotherapy, followed by 4 mg orally twice daily for up to 5 days after a course of treatment.
Elderly: ZETRON is well tolerated by patients over 65 years and no alteration of dosage, dosing frequency or route of administration are required.
Post-operative nausea and vomiting: Adults: For prevention of post-operative nausea and vomiting: 4 mg given by intramuscular or slow intravenous injection at the induction of anaesthesia or as a single dose of 16 mg given orally one hour prior to anaesthesia.
For treatment of established post-operative nausea and vomiting: A single dose of 4 mg given by intramuscular or slow intravenous injection is recommended.
Children and elderly: There is limited experience in the use of ondansetron in the prevention and treatment of post-operative nausea and vomiting. Not recommend for children and elderly use.
Patients with hepatic impairment: Clearance of ondansetron is significantly reduced and serum-half-life significantly prolonged in subjects with moderate or severe impairment of hepatic function. A total daily dose of 8 mg should not be exceeded.
Compatibility: ZETRON injection should be admixed with the following infusion fluids and has been shown to be stable for 7 days in a refrigerator: Sodium chloride intravenous infusion BP 0.9% w/v, Glucose intravenous infusion BP 5% w/v, Mannitol intravenous infusion BP 10% w/v, Ringers intravenous infusion, Potassium chloride 0.3% w/v and Sodium chloride 0.9% w/v intravenous infusion BP, Potassium chloride 0.3% w/v and Glucose 5% w/v intravenous infusion BP.