alkaloid

Camptothecin is a kind of alkaloid proposed from the seed or root bark of the deciduous plant Camptotheca daviae. It can directly destroy the DNA structure and bind to DNA, making DNA vulnerable to endonuclide attack, while inhibiting DNA polymerase and affecting DNA replication. It is mainly sensitive to proliferating cells and is a cell cycle specific drug that acts on the S phase. It has slight lethality to G1, G2 and M phase cells. It has an inhibitory effect on a variety of animal tumors, has no cross-resistance with common antitumor drugs, and can reduce toxicity without reducing efficacy when combined with glycyrrhizin monoamine salt.

The mechanism of topical treatment of psoriasis is to inhibit the mitosis of rapidly dividing keratinocytes, make the proliferative spinous cell layer thin, disappear the keratinization, and restore the formation of granular layer to achieve therapeutic effect. After intravenous injection, most of the drugs bind to plasma protein, the half-life in plasma, kidney and liver is 30 minutes, and the content of gastrointestinal, bone marrow and kidney is the highest. The product is excreted slowly, mainly by urine in its original form, and 17% can be excreted within 48 hours. It is mainly used for gastric cancer, colon cancer, rectal cancer, head and neck cancer and bladder cancer.

Light yellow acicular crystal. Melting point 264 ~ 267℃, [α]D20+31.3°(chloroform: methanol =1∶2). Insoluble in water, soluble in chloroform, methanol, ethanol. The solution shows purple-blue fluorescence under ultraviolet lamp, easily metamorphic in light, slightly hygroscopic, yellowish-green in case of concentrated sulfuric acid, diluted with distilled water to produce yellowish-green fluorescence, which is alkaline. It reacts with bismuth potassium iodide to form an orange-red double salt precipitate. It is obtained by extracting the root or fruit powder in organic solvent. It is highly toxic and should be extracted with care. It has anti-tumor activity. Used to treat bowel cancer, rectal cancer, gastric cancer and leukemia, 10-hydroxycamptothecin is less toxic.

Functional indications

1. It is mainly used for digestive tract tumors, and has good effect on gastric cancer, rectum and colon cancer, which can improve the chance of surgical resection of advanced gastric cancer.

2. It has certain curative effect on cylindroid adenocarcinoma of head and neck, bladder and lung.

3. For primary liver cancer, it can shrink the tumor, and intravenous injection of camptothecin emulsion can increase the chance of surgical resection of liver cancer, and it is also effective for malignant mole and chorionic epithelial carcinoma. Antitumor alkaloids.

4. Irreversibly binds to the DNA-topoisomerase I complex, inhibits DNA recombination after topoisomerase I cleavage, and makes the enzyme form covalent connections with DNA. A cytotoxic antitumor drug.

Matters needing attention

1. Taking sodium bicarbonate alkalized urine and drinking more water can reduce urinary toxicity, and renal insufficiency or urinary infection can be used slowly.

2, can be used to improve the blood image of Chinese and Western medicine such as Lixuesheng, chicken spatholobi, knotweed, yellow essence and so on.

3, stop in time when diarrhea, and symptomatic treatment.

4, white blood cells dropped to 2×109/L should stop the drug, pregnant women should not use.

5, this product can not be diluted with glucose solution and acidic drug solution, should be diluted with normal saline. Dilute immediately after injection, should not be prolonged.