Vincristine is only found in individuals that have used or taken this drug. It is an antitumor alkaloid isolated from Vinca Rosea. (Merck, 11th ed.) 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. Vincristine is indicated for the treatment of acute leukaemia, malignant lymphoma, Hodgkin's disease, acute erythraemia, and acute panmyelosis. Vincristine sulfate is often chosen as part of polychemotherapy because of lack of significant bone marrow suppression (at recommended doses) and of unique clinical toxicity (neuropathy).
belongs to the class of organic compounds known as dipeptides. These are organic compounds containing a sequence of exactly two alpha-amino acids joined by a peptide bond.
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.
Metabolism
Hepatic. Cytochrome P450 isoenzymes of the CYP3A subfamily facilitate the metabolism of vincristine.
Route of Elimination: The liver is the major excretory organ in humans and animals. 80% of an injected dose of vincristine sulfate is excreted via feces. 10 - 20% is excreted via urine.
Half Life: When intravenously injected into cancer patients, a triphasic serum decay patten was observed. The initial, middle, and terminal half-lives are 5 minutes, 2.3 hours, 85 hours respectively. The range of the terminal half-life is humans is 19 - 155 hours.
Vincristine sulfate is not classifiable as to its carcinogenicity to humans (Group 3). Vincristine is part of MOPP, a combination chemotherapy regimen that is carcinogenic to humans (Group 1). (5)
Uses/Sources
Treatment of acute lymphocytic leukemia (ALL), Hodgkin lymphoma, non-Hodgkin lymphomas, Wilms' tumor, neuroblastoma, rhabdomyosarcoma. Liposomal vincristine is indicated for the treatment of relapsed Philadelphia chromosome-negative (Ph-) acute lymphoblastic leukemia (ALL).
