Posology : מינונים

4.2     Posology and Method of Administration
Posology
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: Zofran can be given either by oral (tablets), intravenous or intramuscular administration.

The recomended oral dose is: 8 mg taken 1 to 2 hours before chemotherapy or radiation treatment, followed by 8mg every 12 hours for a maximum of 5 days to protect against delayed or prolonged emesis.

For highly emetogenic chemotherapy To protect against delayed or prolonged emesis after the first 24 hours, oral treatment with Zofran may be continued for up to 5 days after a course of treatment.

The recommended dose for oral administration is 8mg to be taken twice daily.

Paediatric Population

Ondansetron may be administered as a single intravenous dose of 5 mg/m2 immediately before chemotherapy, followed by 4 mg orally twelve hours later.
4 mg orally twice daily can be continued for up to 5 days after a course of treatment.

Elderly

Zofran is well tolerated by patients over 65 years. 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 Zofran 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 8mg 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 16mg taken one hour prior to anaesthesia.

For the treatment of established PONV, intravenous or intramuscular administration is recommended.
Children and Adolescents aged 2 years and over

No studies have been conducted on the use of orally administered ondansetron in the prevention or treatment of post operative nausea and vomiting; slow i.v.
injection is recommended for this purpose.


Elderly
There is limited experience in the use of Zofran in the prevention and treatment of post-operative nausea and vomiting in the elderly, however Zofran 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 Zofran 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 8mg 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.