pms-Ondansetron Dosage/Direction for Use

Note: pms-ONDANSETRON is only available in tablet form. Therefore, when an ondansetron injection is recommended, a product monograph for ondansetron hydrochloride injection should be consulted.
Dosing Considerations: pms-ONDANSETRON has a dose-dependent QTc prolongation effect. For IV administration, the effect is expected to be greater with a faster rate of infusion. Using the minimum effective dose and a slow rate of infusion should always be favored.
Recommended Dose and Dosage Adjustment: Chemotherapy-Induced Nausea and Vomiting: Use in Adults: Highly Emetogenic Chemotherapy (e.g., regimens containing cisplatin): Initial Dose for Prevention of Emesis during the First 24 h Following Chemotherapy: pms-ONDANSETRON (ondansetron hydrochloride) should be given as an initial dose prior to chemotherapy, followed by a dosage regimen tailored to the anticipated severity of emetic response caused by different cancer treatments. The usual dose is ondansetron hydrochloride 8 mg infused intravenously over 15 minutes given at least 30 minutes prior to chemotherapy.
Doses of greater than 8 mg and up to a maximum of 16 mg of ondansetron hydrochloride may only be given by IV infusion. A single-dose greater than 16 mg should not be given due to the dose-dependent risk of QTc prolongation (see Cardiovascular: QTc Interval Prolongation under Precautions; Drug-Drug Interactions: QTc-Prolonging Drugs under Interactions; Pharmacology: Pharmacodynamics: Electrocardiography under Actions).
The efficacy of ondansetron hydrochloride 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.
Post-chemotherapy: After the first 24 hours, pms-ONDANSETRON 8 mg may be taken orally every 8 hours¹ for up to 5 days.
¹ The efficacy of twice daily dosage regimens for the treatment of post-chemotherapy emesis has been established only in adult patients receiving less emetogenic chemotherapy. The appropriateness of twice versus three times daily dosage regimens for other patient groups should be based on an assessment of the needs and responsiveness of the individual patient.
Less Emetogenic Chemotherapy (e.g., regimens containing cyclophosphamide, doxorubicin, epirubicin, fluorouracil and carboplatin): Initial Dose: Ondansetron hydrochloride 8 mg infused intravenously over 15 minutes, given at least 30 minutes prior to chemotherapy or pms-ONDANSETRON 8 mg orally 1 to 2 hours prior to chemotherapy.
Post-chemotherapy: pms-ONDANSETRON 8 mg orally twice daily for up to 5 days.
Use in Children: Clinical experience of ondansetron hydrochloride for the treatment of Post-Chemotherapy Induced Nausea and Vomiting in children is currently limited; however, ondansetron hydrochloride was effective and well-tolerated when given to children 4 to 12 years of age. Ondansetron hydrochloride injection should be given intravenously at a dose of 3 to 5 mg/m² over 15 minutes at least 30 minutes before chemotherapy. After therapy, pms-ONDANSETRON 4 mg should be given orally every 8 hours² for up to 5 days. For children 3 years of age and younger, there is insufficient information available to make dosage recommendations; therefore, pms-ONDANSETRON is not indicated for the treatment of children 3 years of age or younger (see Indications/Uses).
Use in Elderly: Oral Formulations: Efficacy and tolerance in patients aged over 65 years were similar to that seen in younger adults indicating no need to alter dosage schedules in this population.
IV Formulation: In patients 65 years of age or older, all IV doses should be diluted in 50 mL to 100 mL of 0.9% Sodium Chloride Injection or 5% Dextrose Injection.
Radiotherapy-Induced Nausea and Vomiting: Use in Adults: Initial Dose: pms-ONDANSETRON 8 mg orally 1 to 2 hours before radiotherapy.
Post-radiotherapy: pms-ONDANSETRON 8 mg orally every 8 hours² for up to 5 days after a course of treatment.
² The efficacy of twice daily dosage regimens for the treatment of post-chemotherapy emesis has been established only in adult patients receiving less emetogenic chemotherapy. The appropriateness of twice versus three times daily dosage regimens for other patient groups should be based on an assessment of the needs and responsiveness of the individual patient.
Use in Children: There is no experience in clinical studies in this population. pms-ONDANSETRON is not indicated for the prevention and treatment of radiotherapy induced nausea and vomiting in children (see Indications/Uses).
Use in Elderly: Efficacy and tolerance in patients aged over 65 years were similar to that seen in younger adults; indicating no need to alter dosage schedules in this population.
Post-Operative Nausea and Vomiting: Use in Adults: For prevention of post-operative nausea and vomiting pms-ONDANSETRON may be administered as a single dose of 16 mg given orally one hour prior to anaesthesia. Alternatively, a single dose of 4 mg of ondansetron hydrochloride, undiluted may be injected intravenously preferably over 2 to 5 minutes, and not less than 30 seconds, at induction of anaesthesia.
For the treatment of established post-operative nausea and vomiting, a single dose of 4 mg of ondansetron hydrochloride, undiluted injected intravenously preferably over 2 to 5 minutes, and not less than 30 seconds, is recommended.
Use in Children: There is no experience in the use of ondansetron hydrochloride in the prevention and treatment of post-operative nausea and vomiting in children. Ondansetron hydrochloride is not indicated for this use in children (see Indications/Uses).
Use in Elderly: There is limited experience in the use of ondansetron hydrochloride in the prevention and treatment of post-operative nausea and vomiting in the elderly. Ondansetron hydrochloride is not indicated for this use in the elderly (see Indications/Uses).
Patients with Renal/Hepatic Impairment: Use in Patients with Impaired Renal Function: No alteration of daily dosage, frequency of dosing, or route of administration is required.
Use in Patients with Impaired Hepatic Function: The clearance of an 8 mg IV dose of ondansetron hydrochloride was significantly reduced and the serum half-life significantly prolonged in subjects with severe impairment of hepatic function. In patients with moderate or severe impairment of hepatic function, reductions in dosage are therefore recommended and a total daily dose of 8 mg should not be exceeded. This may be given as a single IV or oral dose.
No studies have been conducted to date in patients with jaundice.
Patients with Poor Sparteine/Debrisoquine Metabolism: The elimination half-life and plasma levels of a single 8 mg IV dose of ondansetron did not differ between subjects classified as poor and extensive metabolisers of sparteine and debrisoquine. No alteration of daily dosage or frequency of dosing is recommended for patients known to be poor metabolisers of sparteine and debrisoquine.