Posology
Oral use.
Chemotherapy and Radiotherapy induced nausea and vomiting (CINV and RINV)
Adults:
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.
Emetogenic chemotherapy and radiotherapy:
Ondansetron can be given either by rectal, oral (tablets or syrup), intravenous or intramuscular administration.
The recommended oral dose is 8mg taken 1 to 2 hours before chemotherapy or radiation treatment, followed by 8 mg every 12 hours for a maximum of 5 days to protect against delayed or prolonged emesis.
For highly emetogenic chemotherapy a single dose of up to 24 mg ondansetron taken with 12 mg oral dexamethasone sodium phosphate, 1 to 2 hours before chemotherapy, may be used.
To protect against delayed or prolonged emesis after the first 24 hours, oral or rectal treatment with ondansetron may be continued for up to 5 days after a course of treatment.
The recommended dose for oral administration is 8 mg to be taken twice daily.
Paediatric population:
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 – see below. 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.
Weight-based dosing results in higher total daily doses compared to BSA-based dosing (see section 4.4).
There are no data from controlled clinical trials on the use of ondansetron in the prevention of delayed or prolonged CINV. There are no data from controlled clinical trials on the use of ondansetron for radiotherapy-induced nausea and vomiting in children.
Dosing by BSA:
Ondansetron should be administered immediately before chemotherapy as a single intravenous dose of 5 mg/m2. The single intravenous dose must not exceed 8 mg.
Oral dosing can commence 12 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 | Day1(a,b) | Days 2-6 (b) |
| < 0.6m2 | 5 mg/m2 IV plus 2 mg syrup after 12 hours | 2 mg syrup every 12 hours |
| > 0.6 m2 to ≤ 1.2 m2 | 5 mg/m2 IV plus 4 mg syrup or tablet after 12 hours | 4 mg syrup or tablet every 12 hours |
| > 1.2 m2 | 5 mg/m2 or 8 mg IV plus 8 mg syrup or tablet after 12 hours | 8 mg syrup or tablet every 12 hours |
a The intravenous dose must not exceed 8 mg.
b The total dose over 24 hours (given as divided doses) must not exceed adult dose of 32 mg.
Dosing by body weight:
Weight-based dosing results in higher total daily doses compared to BSA-based dosing (see sections 4.4. and 5.1).
Ondansetron should be administered immediately before chemotherapy as a single intravenous dose of 0.15 mg/kg. The single intravenous dose must not exceed 8 mg.
Two further intravenous doses may be given in 4-hourly intervals.
Oral dosing can commence 12 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)
| 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 every 12 hours |
| > 10 kg | Up to 3 doses of 0.15 mg/kg IV every 4 hours | 4 mg syrup or tablet every 12 hours |
a The intravenous dose must not exceed 8 mg.
b The total daily dose over 24 hours (given as divided doses) must not exceed adult dose of 32 mg.
Elderly
No alteration of oral dose or frequency of administration is required.
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 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.
Post-operative nausea and vomiting (PONV):
Adults
For the prevention of PONV, ondansetron can be administered orally or by intravenous or intramuscular injection.
The recommended oral dose is 16 mg taken one hour prior to anaesthesia.
For the treatment of established PONV, intravenous or intramuscular administration is recommended.
Paediatric population:
PONV in children and adolescents (aged 1 month to 17 years)
Oral formulation:
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.
Injection:
For prevention of PONV in paediatric patients having surgery performed under general anaesthesia, a single dose of ondansetron may be administered by slow intravenous 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 anaesthesia.
For the treatment of PONV after surgery in paediatric patients having surgery performed under general anaesthesia, a single dose of ondansetron may be administered by slow intravenous injection (not less than 30 seconds) at a dose of 0.1 mg/kg up to a maximum of 4 mg.
There are no data on the use of ondansetron in the treatment of PONV in children below 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 (PONV) in the elderly, however ondansetron is well tolerated in patients over 65 years receiving chemotherapy.
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 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
The tablets should be swallowed whole with liquid.