Posology : מינונים

4.2   Posology and method of administration

VINCRISTINE SULFATE SHOULD ONLY BE ADMINISTERED INTRAVENOUSLY.
FATAL IF GIVEN BY OTHER ROUTES
See section 4.4 Special warnings and precautions for use.
Posology
Extreme care must be used in calculating and administering the dose to be injected, because overdose can have severe and even fatal results. When used as monotherapy, the dose should be administered at 1 week intervals. In combination with other antineoplastic agents, the dosing frequency depends on the protocol.
The usual dose for adults is 1.4 mg/m² (maximum of 2 mg) once a week.
Children can tolerate a higher dose: 1.5-2.0 mg/m² once per week. For children weighing 10 kg or less, the usual starting dose is 0.05 mg/kg once a week.


Elderly
The normal adult dose is still appropriate in the elderly.

Hepatic impairment
In patients with hepatic impairment or with a direct serum bilirubin value above 3 mg/100 ml a reduction of 50% of the dose of vincristine sulfate is recommended. Because of the hepatic metabolism and biliary excretion of vincristine, reduced doses are recommended in patients with obstructive jaundice or other hepatic impairment. Patients with liver disease sufficient to decrease biliary excretion may experience an increase in the severity of side effects.

In case of severe neurotoxicity, vincristine sulfate should not be administered, particularly in case of paresis. When the complaints decrease after discontinuation of the administration of vincristine sulfate, the treatment may be resumed with 50% of the dose.

Method of administration
Vincristine sulfate should only be used under strict supervision of physicians experienced in the treatment with cytotoxic products.

Intrathecal administration of vincristine results in fatal neurotoxicity.
Vincristine sulfate can be administered intravenously via an infusion or as a bolus injection of at least 1 minute via the line of a running infusion.
Caution: it is extremely important that the needle be properly positioned in the vein before any drug is injected.

Care should be taken to avoid infiltration of subcutaneous tissues. Extravasation during intravenous administration of vincristine sulfate can cause considerable irritation (see section 4.4). In order to prevent vascular irritation, the vein should be flushed well after the administration of vincristine sulfate.

The dose of vincristine sulfate should be calculated and administered with extreme care, because overdose can have severe and even fatal results.

The dose should not be increased beyond the level which produces therapeutic benefit. In general, individual doses should not exceed 2 mg; and white cell counts should be carried out before and after giving each dose.