Mercaptopurine Tablets

Mercaptopurine tablets are cell cycle specific drugs that inhibit the purine synthesis pathway. Their chemical structure is similar to that of hypoxanthine, and therefore they can competitively inhibit the conversion process of hypoxanthine. Once this product enters the body, it must be converted into 6-mercaptopurine ribonucleotides by phosphoribosyltransferase in the cells before it becomes active. There are two main links of action: (1) It inhibits amidotransferase through negative feedback, thereby preventing the conversion of 1-pyrophosphate-5-phosphoribosyl (PRPP) to 1-amino-5-phosphoribosyl (PRA), interfering with the initial stage of purine nucleotide synthesis. (2) Inhibit the mutual conversion between complex purines, that is, it can inhibit the conversion of inosine nucleotides to adenine nucleotides and inosine nucleotides to xanthine nucleotides and guanine nucleotides. At the same time, this product also inhibits the synthesis of coenzyme I (NAD) and reduces the deoxyadenosine triphosphate (dATP) and deoxyguanosine triphosphate (dGTP) necessary for the biosynthesis of DNA, so that tumor cells cannot proliferate. This product is more sensitive to cells in the S proliferation cycle. In addition to inhibiting the synthesis of cell DNA, it also has a mild inhibitory effect on the synthesis of cell RNA. The use of mercaptopurine to treat leukemia often produces drug resistance. The reason may be that mutated leukemia cell lines appear in the body, which lose the ability to convert mercaptopurine into mercaptopurine ribonucleotides. Pharmacokinetics: Oral gastrointestinal absorption is incomplete, about 50%. Widely distributed in body fluids. The plasma protein binding rate is about 20%. The activation and decomposition process of this product after absorption is mainly carried out in the liver. After oxidation and methylation by xanthine oxidase and other enzymes in the liver, it is decomposed into thiouric acid and loses its activity. The half-life after intravenous injection is about 90 minutes, and about half of the amount is rapidly excreted from the kidneys within 24 hours after metabolism, of which 7-39% is excreted as the original drug.

Main ingredient: Mercaptopurine. Molecular formula: C5H4N4SH2O Molecular weight: 170.19

This product is light yellow tablet.

It is suitable for choriocarcinoma, malignant hydatidiform mole, acute lymphocytic leukemia, acute non-lymphocytic leukemia, and the blast crisis of chronic myeloid leukemia.

1. Choriocarcinoma: Common dosage for adults: 6 mg to 6.5 mg/kg per day, taken orally in two divided doses. A course of treatment is 10 days, with an interval of 3 to 4 weeks. 2. Leukemia: (1) Initially, 2.5 mg/kg or 80 to 100 mg/m2 per day, taken once a day or in divided doses. Generally, significant effects can be seen 2 to 4 weeks after medication. If there is no clinical improvement and a decrease in white blood cell count after 4 weeks of medication, consider increasing the dosage to 5 mg/kg per day under careful observation; (2) Maintenance: 1.5 mg to 2.5 mg/kg or 50 mg to 100 mg/m2 per day, taken orally once a day or in divided doses.

1. The most common is bone marrow suppression: there may be a decrease in white blood cells and platelets; 2. Liver damage: it can cause cholestasis and jaundice; 3. Digestive system: nausea, vomiting, loss of appetite, stomatitis, diarrhea, but it rarely occurs and can be seen in patients who take too much medicine. 4. Hyperuricemia: it is more common in the early stage of leukemia treatment, and severe cases may cause uric acid nephropathy; 5. Interstitial pneumonia and pulmonary fibrosis are rare.

Patients with known hypersensitivity to this product are contraindicated.

Precautions for children: Common dosage for children: 1.5 mg to 2.5 mg/kg or 50 mg/m2 per day, orally once a day or divided into two doses. Precautions for pregnancy and lactation: This product increases the risk of fetal death and congenital malformations, so it is contraindicated during pregnancy. Precautions for the elderly: Because elderly patients have poor tolerance to chemotherapy drugs, when taking this product, supportive therapy must be strengthened, and dynamic changes in symptoms, signs, and peripheral blood vessels must be closely observed.

1. When taken simultaneously with allopurine, the latter inhibits the metabolism of mercaptopurine, significantly increasing the efficacy and toxicity of mercaptopurine; 2. When this product is taken simultaneously with drugs that are toxic to hepatocellular cells, there is a risk of increased toxicity to hepatocellular cells; 3. When this product is used in combination with other anti-tumor drugs or radiotherapy that suppress the bone marrow, the effect of mercaptopurine will be enhanced, so it is necessary to consider adjusting the dosage and course of treatment of this product.

Keep away from light and store in sealed container.

50mg

Tentative 36 months

Zhejiang Zhebei Pharmaceutical Co., Ltd.

• Founded in:

  2000-09-04

• Address:

  Sanlitang, Qianyuan Town, Deqing County, Zhejiang Province

• Tax NO.:

  913305007195378967

• Registered Funds:

  61.282052 million yuan

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