What Is Vincristine?

Vincristine (Vincristine, Oncovin, VCR) is an alkaloid extracted from vinca flowers of the Apocynaceae plant. Due to its good antitumor effect, its preparations are currently used as clinical antitumor drugs. It is found in the periwinkle of the oleander plant. Needle-like crystals when recrystallized from methanol. Melting point is 211 to 216 ° C, and specific rotation is + 42 ° (chloroform).

Vincristine is anti-cancer and has a curative effect

Vincristine is a bisindole alkaloid. Soluble in chloroform,

The vinca coarse powder is stirred with water, left for a while, and cold soaked with benzene.

Currently the direct medicinal product is Vincristine Sulfate Injection. Although vincristine has a good antitumor effect, it has large toxic and side effects, mainly neurotoxicity. Research is now moving towards vincristine liposomes to reduce the neurotoxicity of vincristine. Liposome is a targeted drug carrier, belonging to

[Indications]

. Acute leukemia, especially childhood acute leukemia, has a significant effect on acute lymphocytic leukemia. . Malignant lymphoma. . Germ cell tumor. . Small cell lung cancer, Ewing sarcoma, nephroblastoma, neuroblastoma. . Breast cancer, chronic lymphocytic leukemia, gastrointestinal cancer, melanoma and multiple myeloma.

chemical composition

The chemical name of this product is Vincristine sulfate.

Molecular formula: C ₄₆ H ₅₆ NO ₁₀ · H ₂ SO ₄

Molecular weight: 923.04 ^[1]

medicine interactions

1 Pyrrole series of antifungal agents (Itraconazole), increase the side effects of the muscular nervous system. If side effects are found, appropriate treatment such as reduction, suspension or withdrawal should be carried out. Itraconazole has the effect of hindering liver cytochrome P-4503A. Vincristine is metabolized by hepatocyte chromatin P-4503A, and combined use can inhibit the metabolism of vincristine.

2 Combined with phenytoin sodium to reduce phenytoin sodium absorption or increase metabolism.

3 Combination with platinum-containing anti-sub-malignant tumors may enhance the 8th pair of neurological disorders.

4 In combination with L-asparaginase, it may strengthen nervous system and blood system disorders. To minimize toxicity, vincristine sulfate can be used 12-24 hours before L-asparaginase administration.

5 Vincristine is widely used in chemotherapy regimens for cancer, but due to the severe bone marrow suppression, gastrointestinal reactions and liver and kidney damage in chemotherapy, it is necessary to cooperate with taking selenium supplements and use selenium to help control the condition It can repair the function of the stomach and intestines, and improve immunity. At the same time, it can stimulate the bone marrow and restore the hematopoietic function of the bone marrow. In addition, it can improve the tolerance of cells to the toxicity of chemical drugs, reduce side effects and enhance the effect of chemotherapy. ^[2]

Adverse reactions

1 Dose-limiting toxicity is neurotoxicity, which mainly causes peripheral neurological symptoms, such as finger and neurotoxicity, and is related to the cumulative amount. Toes are numb, tendon reflexes are dull or disappear, and peripheral neuritis. Abdominal pain, constipation, and occasional paralytic intestinal obstruction. Motor nerves, sensory nerves and brain nerves can also be disrupted and produce corresponding symptoms. Neurotoxicity often occurs in people over 40 years of age. Children are better tolerated than adults. Patients with malignant lymphoma are more likely to develop neurotoxicity than patients with other tumors.

2 Bone marrow suppression and lighter digestive tract response.

3 It has local tissue stimulating effect, and the liquid medicine cannot leak out, otherwise it may cause local necrosis.

4 Hair loss is seen, with occasional changes in blood pressure.

[Pharmacological Theory]

Vincristine is rapidly distributed in various tissues after intravenous injection, and the concentration in nerve cells is relatively high, and rarely penetrates the blood-brain barrier. The concentration of cerebrospinal fluid is 1/30 to 1/20 of the plasma concentration. Protein binding rate was 75%. In adults, T1 / 2 is less than 5 minutes, T1 / 2 is 50-155 minutes, and the peripheral elimination phase T1 / 2 is as long as 85 hours. Metabolized in the liver, the highest concentration in bile, mainly excreted with bile, fecal excretion

Vincristine pharmacological effects

70% of excretion, 5% to 16% excretion in urine. Vincristine can be selectively concentrated in cancer tissues, which can synchronize proliferating cells, thereby increasing the effectiveness of antitumor drugs. ^[2]

Instructions for use

Injection: 1mg. Intravenous, 1.4mg / once, once a week, the total amount of 20 ~ 30mg is a course of treatment.

[Pharmacological action]

Vincristine is an effective component extracted from vinca flowers of the oleander family. It also has effects on mouse Ridgeway osteosarcoma, Mecca lymphosarcoma, and X-5563 myeloma. Vincristine has obvious anti-cancer effect on the cultured human liver cancer cell line (SMMC-7721). When Vincristine has a concentration of 100ng / ml and 50ng / ml, it can make most cancer cells round. The envelope thickens and falls off into suspension. At concentrations of 100ng / ml and 50ng / ml, most tumor cells can be rounded, their cell membranes can be thickened, and they fall off in suspension. Vincristine concentration of 100ng / ml on the cells on the second day and 50ng / ml on the 6th day, the cell proliferation inhibition rate is very obvious {inhibition rate 50%}, Vincristine 100ng / ml concentration on the 8th day Since then, the proliferation inhibition rate has reached 99.64%. At the same time, with the increase of VCR concentration, when the protein content inhibition rate increased to 75.21% (25ng / ml), the killing rate of cancer cells also increased. Vincristine has a strong inhibitory effect on the human retinoblastoma cell line HOX-Rb44. The IC50 of half-inhibition concentration is 0.31ug / ml, and the concentration of vincristine can significantly induce apoptosis of K562 cells . ^[2]