What Is Vincristine?
Vincristine is an anticancer drug developed by Eli Lilly and Company, an American pharmaceutical company.
It is also known by the trade name Oncovin and is manufactured and marketed in Japan by Nippon Kayaku Co. It is a commonly used drug for hematologic tumors and is listed on the World Health Organization’s (WHO) Model List of Essential Medicines as an important drug.
Vincristine is found in the oleander plant in Nichinichiwa, and is chemically classified as a vinca alkaloid, a plant alkaloid. As an anticancer drug, it is classified as a microtubule polymerization inhibitor and is a deleterious drug.
As a drug, it is only prescribed by a physician and is administered intravenously. It is usually supplied as Vincristine sulfate. The CAS number is 2068-78-2.
Uses of Vincristine
1. Anticancer Agents
Vincristine is used as an anticancer agent. As a pharmaceutical product, Vincristine is indicated in Japan as of 2022 for the treatment of leukemia, malignant lymphoma pediatric oncology, multiple myeloma malignant astrocytoma, glioma with oligodendroglioma component in combination with other antineoplastic agents, and pheochromocytoma.
2. For Investigational Studies
Vincristine is also used as an anti-tumor agent for experimental research and as a reagent in cytoskeletal research when microtubule polymerization inhibition is performed. It is also sold as a reagent for experimental studies.
3. Therapeutic Use in Animals
Vincristine is sometimes used in the treatment of malignant lymphoma in dogs and other pet animals. In recent years, there has been a growing awareness of the possibility of somehow treating cancer in pet animals (with the hope of prolonging their lives).
Although Vincristine is not an official veterinary drug, there are currently no anti-cancer drugs for animals. Therefore, human drugs may be used by veterinarians.
Characteristics of Vincristine
Vincristine’s mechanism of action is the inhibition of microtubule polymerization. Mitosis of cells requires the formation of a spindle. The spindle is formed by the attachment of microtubules to chromosomes and the polymerization and depolymerization of microtubules to form a spindle thread.
Vincristine binds to microtubules and causes abnormalities in the structure and function of the spindle, resulting in the arrest of mitosis in the mid-mitotic (M) stage of the cell. The mitotic arrested cells are induced to apoptosis.
In this way, tumor cell proliferation is suppressed and the cells are killed. However, since it also inhibits cell division of normal cells, the concern is that it affects not only tumor cells but also normal cells. This can cause side effects.
Other Information About Vincristine
1. Side Effects of Vincristine
Vincristine also inhibits cell division of normal cells, which may cause side effects such as hair loss (alopecia) and a decrease in white blood cell count (myelosuppression). This is a common characteristic of anticancer agents.
Peripheral neuropathy is also known as a frequent side effect. Clinically, this is felt as numbness in the hands and feet and loss of sensation in the fingers. This symptom can have a significant impact on the lives of those undergoing treatment, such as difficulty in performing personal tasks and burns or injuries due to lack of sensation.
There is also a high likelihood that the condition will worsen with continued administration. Therefore, dosage should be reduced or discontinued when this symptom is observed.
Peripheral neuropathy is also seen with other phytoalkaloid microtubule polymerization inhibitors and is thought to be due to the drug also binding to the microtubules of peripheral nerves, causing axonal degeneration. Another common side effect is constipation.
2. Vincristine and Multiple Therapy
Vincristine is often used in combination with other anticancer agents that have different mechanisms of action. The objective is to inhibit the growth of cancer effectively by having multiple actions work simultaneously.
For example, in lymphoma, it is used in combination with cyclophosphamide, which methylates DNA, doxorubicin, which gets between DNA structures, and oxaliplatin, which forms cross-links in DNA. Because anticancer drugs have strong side effects, the actual dosage of combination therapy used is carefully considered and determined.