Vinblastine
Vinblastine is a Vinca alkaloid work by inhibiting mitosis (cell division) in
metaphase. Alkaloids bind to tubulin, thus preventing the cell from making
the spindles it needs to be able to move its chromosomes around as it
divides. The alkaloids also seem to interfere with cells' ability to synthesize
DNA and RNA. Administered intravenously in their sulfate form the solution
is fatal if administered any other way, and can cause a lot of tissue irritation
if they leak out of the vein.
Vinblastine is typically administered at a dose of 6 milligrams per square
meter of body surface. Marketed as Velban by Eli Lilly and has a half-life
in the bloodstream of 24 hours. Vinblastine is mainly useful for treating
Hodgkin's disease, lymphocytic lymphoma, histiocytic lymphoma,
advanced testicular cancer, advanced breast cancer, Kaposi's sarcoma,
and Letterer-Siwe disease.
It also seems to fight cancer by interfering with glutamic acid metabolism
(specifically, the pathways leading from glutamic acid to the Krebs cycle
and to urea formation). People with bacterial infections should not be
given this drug, nor should pregnant women, since it caused severe birth
defects in animal studies. Side effects include hair loss, nausea, lowered
blood cell counts, headache, stomach pain, numbness, constipation and
mouth sores. Bone marrow damage is the typical dose-limiting factor.