Crizler

Indications

Vincristine Sulfate is a chemotherapy medicine used, usually in combination with other cancer medicines, to treat acute leukaemias (especially acute lymphoblastic leukaemia), Hodgkin and non Hodgkin lymphomas, and several childhood and adult solid tumours such as Wilms tumour, neuroblastoma, rhabdomyosarcoma and Ewing sarcoma. It may also be used in certain blood disorders, as decided by a specialist.

How It Works

Vincristine is a vinca alkaloid, originally obtained from the periwinkle plant. It binds to tubulin and stops cells from building the microtubules they need to separate their chromosomes during division. As a result, rapidly dividing cancer cells cannot divide and die.

Dosage and Administration

Vincristine is given only by trained doctors or nurses as an injection or short infusion into a vein, usually once a week or according to the treatment protocol. The dose is calculated from body surface area and is usually capped at a maximum single dose. It must be given into a vein only. Giving it into the spine (intrathecally) is fatal, so it is prepared and labelled with special safety checks. Dosing is as prescribed.

Interactions

• Strong CYP3A4 inhibitors such as Itraconazole, Ketoconazole, Posaconazole, Voriconazole and Clarithromycin can greatly increase nerve toxicity and should be avoided.
• Phenytoin levels may fall during treatment.
• Other medicines that damage nerves or hearing may add to side effects.
• Live vaccines must be avoided during treatment.

Contraindications

• Allergy to Vincristine.
• The demyelinating form of Charcot Marie Tooth disease or other serious nerve disease.
• Injection into the spine (intrathecal use) under any circumstances.

Side Effects

The main side effects affect the nerves: tingling or numbness in the fingers and toes, loss of reflexes, weakness, jaw pain, constipation, abdominal cramps, drooping eyelids or hoarse voice. Hair loss is common. Other effects include low sodium, problems passing urine, and pain or tissue damage if the drug leaks outside the vein. It usually causes less bone marrow suppression than many other chemotherapy medicines.

Get urgent medical help if you develop severe constipation or abdominal pain with no bowel movement for several days, difficulty walking or holding objects, fever of 38°C or more, severe pain or blistering at the injection site, vision changes, fits, or signs of an allergic reaction.

Pregnancy and Lactation

Vincristine can harm an unborn baby. Effective contraception is needed during treatment and for several months after (as advised by the cancer team). Breastfeeding must stop during treatment.

Precautions and Warnings

• A bowel routine with laxatives is usually started to prevent severe constipation.
• Nerve symptoms are checked before each dose and the dose may be reduced or stopped.
• Use with care in liver disease, as lower doses may be needed.
• Leakage outside the vein can cause serious tissue damage; tell the nurse at once if the drip site hurts.
• Handled only by trained staff with safety precautions; avoid contact with eyes.

Overdose

Overdose can cause severe nerve damage, paralysis of the bowel, fits, low sodium and serious illness. There is no antidote; hospital staff will provide intensive supportive care.

Therapeutic Class

Antineoplastic, vinca alkaloid.

Storage

Hospital medicine: store in a fridge at 2 to 8°C, do not freeze, protected from light, as directed on the pack and out of the reach of children.