BIOCRISTIN-AQ INJECTION 1MG/1ML

Indications

• Acute lymphoblastic leukemia
• Hodgkin's lymphoma
• Non-Hodgkin's lymphoma
• Wilms' tumor
• Neuroblastoma
• Kaposi's sarcoma
• Testicular cancer

Mechanism of action

Vincristine exerts its antitumor effects primarily through the inhibition of mitosis at the metaphase stage by binding to tubulin, which prevents the proper polymerization of microtubules. This disruption of the mitotic spindle leads to cell cycle arrest, preventing proper segregation of chromosomes and ultimately resulting in cellular death. Vincristine may also interfere with several metabolic pathways, including amino acid and cyclic AMP metabolism, and has been noted to have some immunosuppressive properties.

Pharmacodynamics

As a vinca alkaloid, vincristine demonstrates specific activity against various malignancies, including breast cancer, Hodgkin's disease, Kaposi's sarcoma, and testicular cancer. Its structural composition allows it to bind effectively to microtubule proteins, leading to crystallization and mitotic arrest. The drug has been clinically used since the discovery of its antitumor properties in 1959, and despite initial investigations for other properties, its effectiveness against tumors has made it a cornerstone in cancer chemotherapy. Vincristine is classified as a cell cycle phase-specific agent, targeting mitosis.

Pharmacokinetics

Vincristine is administered intravenously and has a variable bioavailability due to significant first-pass metabolism. It is metabolized in the liver, primarily by cytochrome P450 enzymes, and has a half-life of approximately 20 to 40 hours. The drug is excreted mainly in the bile, with minimal renal excretion. Its pharmacokinetic profile can be influenced by various factors, including concurrent medications that may alter its metabolism or exposure.

Adverse effects

• Constipation
• Neuropathy
• Alopecia
• Nausea
• Vomiting
• Bone marrow suppression
• Severe neurotoxicity

Interactions

• asparaginase+vincristine: Unknown (increases risk of neurotoxicity)
• crisantaspase+vincristine: Unknown (increases risk of neurotoxicity)
• mitotane+vincristine: Unknown (decreases exposure)
• pegaspargase+vincristine: Unknown (increases risk of neurotoxicity)
• rifampicin+vincristine: Unknown (decreases exposure)
• stjohn’swort+vincristine: Unknown (decreases exposure)

Precautions

• Monitor for signs of neurotoxicity
• Caution in patients with pre-existing neuropathies
• Use with caution in patients with hepatic impairment

Pregnancy

Vincristine is classified as a Category D drug. It should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

It is not known whether vincristine is excreted in human milk. Caution is advised if the drug is administered to a nursing woman.

Storage

Store at room temperature, away from light and moisture. Protect from freezing.

Formulations

• Injection solution

Mechanism of action

The antitumor activity of Vincristine is thought to be due primarily to inhibition of mitosis at metaphase through its interaction with tubulin. Like other vinca alkaloids, Vincristine may also interfere with: 1) amino acid, cyclic AMP, and glutathione metabolism, 2) calmodulin-dependent Ca²⁺-transport ATPase activity, 3) cellular respiration, and 4) nucleic acid and lipid biosynthesis. Vinca alkaloids are cell cycle specific agents ... /which/ block mitosis and produce metaphase arrest. Biological activities of these drugs can be explained by their ability to bind specifically tubulin, and to block ability of the protein to polymerize into microtubules ... through disruption of microtubules of mitotic apparatus, cell division is arrested in metaphase. In absence of intact mitotic spindle, chromosomes may disperse throughout cytoplasm ... or may occur in unusual groupings ... inability to segregate chromosomes correctly during mitosis presumably leads to cellular death. /Vinca alkaloids/ Although the mechanism of action has not been definitely established, vincristine appears to bind to or crystallize critical microtubular proteins of the mitotic spindle, thus preventing their proper polymerization and causing metaphase arrest. In high concentrations, the drug also exerts complex effects on nucleic acid and protein synthesis. Vincristine exerts some immunosuppressive activity.

Pharmacodynamics

Vincristine is a vinca alkaloid antineoplastic agent used as a treatment for various cancers including breast cancer, Hodgkin's disease, Kaposi's sarcoma, and testicular cancer. The vinca alkaloids are structurally similar compounds comprised of 2 multiringed units, vindoline and catharanthine. The vinca alkaloids have become clinically useful since the discovery of their antitumour properties in 1959. Initially, extracts of the periwinkle plant (Catharanthus roseus) were investigated because of putative hypoglycemic properties, but were noted to cause marrow suppression in rats and antileukemic effects <i>in vitro</i>. Vincristine binds to the microtubular proteins of the mitotic spindle, leading to crystallization of the microtubule and mitotic arrest or cell death. Vincristine has some immunosuppressant effect. The vinca alkaloids are considered to be cell cycle phase-specific.