Velvin Injection

Although the mechanism of action has not been definitely established, VinBLAStine appears to bind to or crystallise critical microtubular proteins of the mitotic spindle, thus preventing their proper polymerisation and causing metaphase arrest. In high concentrations, Vinblastine also exerts complex effects on nucleic acid and protein synthesis. Vinblastine reportedly also interferes with amino acid metabolism by blocking cellular utilisation of glutamic acid and thus inhibits purine synthesis, the citric acid cycle, and the formation of urea. Vinblastine exerts some immunosuppressive activity.

The recommended dose for adults, the elderly and children is 6 mg/m2 , usually administered no more frequently than once every seven days. For testicular tumours, the dosage may be increased to 0.2 mg/kg administered on each of two consecutive days every three weeks.

To minimise the possibility of extravascular spillage, it is suggested that the mini-bag infusion and needle be rinsed with venous blood before withdrawal. The dose should not be diluted in large volumes of diluent (ie, 100 to 250 ml) or given intravenously for prolonged periods (ranging from 30 to 60 minutes or more), since this frequently results in irritation of the vein and increases the chance of extravasation.

Because of the enhanced possibility of thrombosis, it is considered inadvisable to inject a solution of VinBLAStine sulphate into an extremity in which the circulation is impaired, or potentially impaired, by such conditions as compressing or invading neoplasm, phlebitis or varicosity.

Possible increase in vinblastine levels with aprepitant. Reduced vinblastine metabolism with miconazole. Variable interactions with phenytoin, monitor serum phenytoin levels. Reduced immune response with vaccines. Additive myelotoxicity with zidovudine. Concurrent admin of vinblastine with CYP3A inhibitors may cause an earlier onset and/or an increased severity of side effects.

Hypersensitivity to the active substance or to any of the excipients.

For intravenous use only. Fatal if given by other routes.

Vinblastine Sulfate is contraindicated in patients who are leucopenic.

Vinblastine Sulfate should not be used in the presence of bacterial infection. Such infections should be brought under control with antiseptics or antibiotics before the initiation of therapy with Vinblastine Sulfate.

Alopecia, constipation, malaise, stomatitis, dose-limiting bone marrow suppression (e.g. granulocytopenia, thrombocytopenia, anaemia), hypertension, central and peripheral neurotoxicity, 8th cranial nerve damage resulting in vestibular and auditory toxicity, ischaemic cardiac toxicity, breathlessness, bone, tumour or jaw pain. Nausea, vomiting, GI bleed, syndrome of inappropriate antidiuretic hormone. Necrosis, cellulitis if extravasation occurs.

Although information on the use of Vinblastine during pregnancy is limited, the drug may cause foetal toxicity when administered to pregnant women. The drug causes resorption of foetuses in animals and produces gross foetal abnormalities in surviving offspring. There are no adequate and controlled studies to date using Vinblastine in pregnant women, and the drug should be used during pregnancy only in life-threatening situations or severe disease for which safer drugs cannot be used or are ineffective. Women of childbearing potential should be advised to avoid becoming pregnant while receiving the drug. If Vinblastine is administered during pregnancy or the patient becomes pregnant while receiving the drug, the patient should be informed of the potential hazard to the foetus.

Breast-feeding: It is not known whether Vinblastine is excreted in human milk. Because of the potential for
serious adverse reactions due to Vinblastine in nursing infants, a decision should be made whether to discontinue nursing or the drug, taking into account the importance of the drug to the mother.

Hepatic impairment; neurotoxicity; ischemic heart disease; preexisting pulmonary dysfunction; extravasation may cause tissue damage and pain. Discontinue immediately if extravasation occurs, with local Inj of hyaluronidase and local heat application to decrease discomfort and risk of cellulitis; remaining Inj to be injected into another vein. Routine prophylaxis against constipation recommended especially in high doses. Nadir in leukocyte count occur 4-10 days after vinblastine admin; recovery observed 7-14 days after treatment.

Cytotoxic Chemotherapy

Store in a refrigerator (2°C-8°C). Keep vial in outer carton in order to protect from light.