Vincristine

Vincristine (Oncovin®) is an alkaloid from the Madagascar periwinkle (Catharanthus roseus, formerly Vinca rosea and hence its name). It is used in chemotherapy.

Mode of action

Vincristine acts by binding to tubulin, the main protein of the cytoskeleton. Microtubule disruption impedes mitosis in metaphase. The vinca alkaloids therefore affect all rapidly dividing cell types, such as intestinal epithelium.

Side-effects

The main side-effects of vincristine are peripheral neuropathy and constipation. The latter may require laxatives, while the former can be a reason to reduce the dose of vincristine.

Uses

Vincristine is used in various types of chemotherapy regimens for tumours such as multiple myeloma (VAD regimen), acute myelogenous leukemia, lymphomas, breast cancer and lung cancer.

History

Having been used as a folk remedy for centuries, the C. roseus turned out to have 70 alkaloids in the 1950. Many are biologically active.

External links

• Vincristine chemotherapy
• Vincristine and vinblastine
• Description and Natural History of the Periwinkle