Vinca alkaloids Vinca alkaloids


The vinca alkaloids vincristine and vinblastine are used for the management of cancer and immune-mediated diseases in cats and dogs. They have been most successful when used against lymphosarcoma and haematopoletic neoplasms, mammary neoplasms in dogs, and some sarcomas. Vincristine has also been used for transmissible venereal tumour in dogs. Vinblastine has been used less often mainly for primary lymphoreticular tumours and disseminated mast cell tumours.

The dose rate of vincristine for dogs and cats is in the range:

0.025-0.05 mg/kg body weight, or

0.50 mg/m2 body surface

The induction dose is usually 8 treatments at 14-21 day intervals.
The dose rate of vinblastine is:

2 mg/m2 body surface every 7-14 days.

Both drugs are administered by slow intravenous infusion. Perivascular leakage should be avoided because they cause local irritation and necrosis, hence use of an i.v. catheter is preferred. They can also be given mixed with isotonic saline and administered over a 4-6-hour period.

Both drugs are metabolised by the liver and excreted via the bile into faeces, so normal liver function is necessary and should be evaluated before their administration.