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 oral dose is 8 mg (10 ml, i.e., two 5 ml spoonfuls) 1-2 hours before treatment, followed by 8 mg (10 ml, i.e., two 5 ml spoonfuls) orally 12 hours later.
Highly emetogenic chemotherapy:
For patients receiving highly emetogenic chemotherapy a single oral dose of up to 24 mg (30 ml, i.e., six 5 ml spoonfuls) ondansetron taken together with 12 mg oral dexamethasone sodium phosphate, 1 to 2 hours before chemotherapy, may be used. After the first 24 hours, oral treatment with ondansetron should be continued for up to 5 days and rectal treatment for up to 3 days after a course of treatment. The recommended oral dose is 8 mg (10 ml, i.e., two 5 ml spoonfuls) to be taken twice daily.
Paediatric Population
CINV in Children and Adolescents (aged 6 months to 17 years):
The dose of CINV can be calculated based on body surface area (BSA) or weight. Weight-based dosing results in higher total daily doses compared to BSA-based dosing (section 4.4 and 5.1).
There are no data from controlled clinical trials on the use of ondansetron in the prevention of chemotherapy-induced delayed or prolonged nausea and vomiting. There are no data from controlled clinical trials on the use of ondansetron for radiotherapy-induced nausea and vomiting in children.
In paediatric clinical studies, ondansetron was given by IV infusion diluted in 25 to 50 ml of saline or other compatible infusion fluid and infused over not less than 15 minutes.
Dosing by Body Surface Area (BSA)
Ondansetron should be administered immediately before chemotherapy as a single IV dose of 5 mg/m2. The single IV dose must not exceed 8 mg.
Oral dosing can commence twelve hours later and may be continued for up to 5 days (Table 1).
The total dose over 24 hours (given as divided doses) must not exceed adult dose of 32 mg.
Table 1. BSA-based dosing for CINV (aged 6 months to 17 years)
| BSA | Day 1 (a, b) | Days 2-6 (b) |
| < 0.6 m2 | 5 mg/m2 IV plus 2 mg syrup (equivalent to 2.5 mls of syrup or the smaller end of spoon supplied in original pack) after 12 hours | 2 mg syrup (equivalent to 2.5 mls of syrup or the smaller end of spoon supplied in original pack) every 12 hours |
| > 0.6 m2 to ≤ 1.2 m2 | 5 mg/m2 IV plus 4 mg syrup (equivalent to 5 mls of syrup or the larger end of spoon supplied in original pack) or one 4 mg tablet after 12 hours | 4 mg syrup (equivalent to 5 mls of syrup or the larger end of spoon supplied in original pack) or one 4 mg tablet every 12 hours |
a The intravenous dose must not exceed 8 mg
b the total dose over 24 hours must not exceed adult dose of 32 mg
Dosing by bodyweight
Weight-based dosing results in higher total daily doses compared to BSA-based dosing (section 4.4 and 5.1).
Ondansetron should be administered immediately before chemotherapy as a single IV dose of 0.15 mg/kg. The single 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 twelve hours later and may be continued for up to 5 days (Table 2). The total dose over 24 hours (given as divided doses) must not exceed adult dose of 32 mg.
Table 2. Weight-based dosing for CINV (aged 6 months to 17 years)
| Body Weight | Day 1 (a, b) | Days 2-6 (b) |
| ≤ 10 kg | Up to 3 doses of 0.15 mg/kg IV every 4 hours | 2 mg syrup (equivalent to 2.5 mls of syrup or the smaller end of spoon supplied in original pack) every 12 hours |
| > 10 kg | Up to 3 doses of 0.15 mg/kg IV every 4 hours | 4 mg syrup (equivalent to 5 mls of syrup or the larger end of spoon supplied in original pack) every 12 hours |
a The intravenous dose must not exceed 8 mg
b the total dose over 24 hours must not exceed adult dose of 32 mg
CINV and RINV in Elderly:
Ondansetron is well tolerated by patients over 65 years of age and no alteration of oral dose or frequency of administration is required.
POST-OPERATIVE NAUSEA AND VOMITING:
PONV in Adults:
For prevention of post-operative nausea and vomiting the recommended oral dose is16 mg (20 ml, i.e., four 5 ml spoonfuls) given one hour prior to anaesthesia.
For treatment of established post-operative nausea and vomiting ondansetron administration by injection is recommended.
Paediatric Population
PONV in Children and Adolescents (aged 1 month to 17 years):
No studies have been conducted on the use of orally administered ondansetron in the prevention or treatment of post-operative nausea and vomiting; slow IV injection (not less than 30 seconds) is recommended for this purpose.
There are no data on the use of ondansetron in the treatment of post-operative nausea and vomiting in children under 2 years of age.
Elderly:
There is limited experience in the use of ondansetron in the prevention and treatment of post-operative nausea and vomiting in the elderly, however ondansetron is well tolerated in patients over 65 years receiving chemotherapy.
PATIENTS WITH RENAL/HEPATIC IMPAIRMENT:
Patients with Renal Impairment:
No alteration of daily dosage or frequency of dosing, or route of administration are required.
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. 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 metabolisers 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.
Method of administration:
► Use the 2.5-5 ml double-ended spoon supplied in the pack (see below) to measure the required dose.
► The solution should be swallowed.
► The spoon should be washed with clean water after taking every dose.
► Once measured, the solution should be consumed within 3 hours
Double-ended Spoon