Mercaptopurine Tablets

It is a cell cycle specific drug that inhibits the purine synthesis pathway. Its chemical structure is similar to that of hypoxanthine, so it can competitively inhibit the conversion process of hypoxanthine. After entering the body, this product must be converted into 6-mercaptopurine ribonucleotide by phosphoribosyltransferase in the cell before it becomes active. It has two main action links: (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) Inhibits 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 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, which may be due to the appearance of mutant leukemia cell lines in the body, which have lost the ability to convert mercaptopurine into mercaptopurine ribonucleotides.

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 adult dose: 6 mg to 6.5 mg/kg per day, taken orally in two divided doses. One course of treatment is 10 days, with an interval of 3 to 4 weeks between courses. 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 no decrease in white blood cell count after 4 weeks of medication, consider increasing the dose 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 leukocytes and platelets; 2. Liver damage: it can cause cholestasis and jaundice; 3. Digestive system: nausea, vomiting, loss of appetite, stomatitis, diarrhea, but these rarely occur and can be seen in patients who take too much medication; 4. Hyperuricemia: more common in the early stages of leukemia treatment, 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: 1.5mg~2.5mg/kg or 50mg/m[sup]2[/sup] daily, orally once a day or divided into several times. 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: This product increases the risk of fetal death and congenital malformations, so it is contraindicated during pregnancy.

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.

50 mg

36 months