Vincristine sulfate

Intravenous
Acute lymphoblastic leukaemia, Acute myeloid leukaemia, Brain tumour, Hodgkin's disease, Neuroblastoma, Non-Hodgkin's lymphoma, Small cell lung cancer, Wilm's tumour

Dose adjustment may be needed. Serum bilirubin >3 mg/100ml: Reduce dose by 50%.

Any solution that may change pH of the solution beyond 3.5-5.5.

Patients with demyelinating form of Charcot-Marie-Tooth syndrome. Pregnancy and lactation. Intrathecal admin (may be fatal). Patients receiving radiation therapy through ports which include liver.

Elderly. Preexisting pulmonary dysfunction or neuromuscular disease; leucopenia or a complicating infection; impaired liver function; obstructive jaundice. Routine prophylactic laxative needed to ensure regular bowel movement. Discontinue immediately if extravasation occurs, and inj any remaining drug into another vein, followed by local Inj of hyaluronidase and topical heat application to the affected area to aid in drug removal and reduce discomfort. Discontinue in patients who develop progressive dyspnea. CBC to be checked before each dose admin. Frequent monitoring of uric acid during first 3-4 wk of treatment and watch out for uric acid nephropathy.

Dose limiting neurotoxicity (e.g. motor function impairment, gait abnormalities), hyperuricaemia, bronchospasm, azospermia, amenorrhoea, alopoecia, leucopenia, urinary dysfunction, abdominal cramps, vomiting, diarrhoea, severe constipation, paralytic ileus, convulsions, hypertension, orthostatic hypotension, ptosis, hoarseness, optic neuropathies, hallucinations, blindness, neurological deafness, difficulty in walking, syndrome of inappropriate ADH secretion.
Potentially Fatal: Myelosuppression.

IV/Parenteral: D

Symptoms: mainly extensions of its common adverse effects. Management: Treatment is supportive and includes prevention of side effects from syndrome of inappropriate antidiuretic hormone secretion (SIADH) (e.g. fluid restriction and admin of loop diuretic); admin of anticonvulsants and use of enemas (to prevent ileus). Closely monitor the CV system and determine the blood counts daily to guide transfusion requirements. Folinic acid 100 mg admin IV every 3 hr for 24 hr and then every 6 hr for at least 48 h may be admin. Haemodialysis unlikely to be useful.

Decreased digoxin (tablets) and verapamil absorption with antineoplastic regimens. Increased etoposide serum levels with vincristine. Increased toxicity when ganciclovir given with, immediately before or after vincristine. Reduced vincristine metabolism with miconazole. Increased neurotoxicity with isoniazid, itraconazole, voriconazole, posaconazole and nifedipine. Decreased immune response when used concurrently with vaccines. Increased myelotoxicity with zidovudine. Increased risk of thromboembolic complications with tamoxifen. Increased risk of ototoxicity with ototoxic drugs (e.g. platinum-containing antineoplastic agents). Possible risk of earlier onset and/or increased severity of adverse effects with macrolides. Possible increase in vincristine levels with aprepitant. Possible decrease in antiepileptic levels with vincristine, monitor serum antiepileptic levels and effectiveness of chemotherapy.
Potentially Fatal: Increased risk of bronchospasm with mitomycin C. Reduced vincristine clearance and increased toxicity with asparaginase, minimise toxicity by giving vincristine 12-24 hr before L-asparaginase admin.

Description: Vincristine arrests cell division at the metaphase stage by inhibiting microtubule formation in the mitotic spindle.
Pharmacokinetics:
Absorption: Poorly absorbed from the GI tract.
Distribution: Does not cross the blood-brain barrier in significant amounts. Protein-binding: Extensive.
Metabolism: Metabolised in liver.
Excretion: Excreted mainly via bile into faeces (as unchanged drug and metabolites, 70-80%), urine; 85 hrs (elimination half-life).

Store at 2-8°C. Protect from light.

Cytotoxic Chemotherapy