cytosar

Cytarabine (Cytarabine) instructions
Common name: Cytarabine
Trade name: Cytosar
Full names: Cytarabine, Cytarabine, Cytarabine, Cytosar

Indications:
Cytarabine is mainly suitable for induction remission and maintenance treatment of acute non-lymphocytic leukemia in adults and children; non-Hodgkin's lymphoma, bone marrow transplant pretreatment, and leukemia brain metastasis. It also has therapeutic effects on other types of leukemia, such as acute lymphoblastic leukemia and chronic myeloid leukemia (blast phase).

Usage and dosage:
1. Common dosage for adults
(1) Induction of remission: intravenous injection or infusion of 2 mg/kg (or 1 to 3 mg/kg of body weight) once a day for 10 to 14 days. If there are no obvious adverse reactions, the dose can be increased to 4 to 6 mg/kg of body weight once.
(2) Maintenance: After complete remission, use maintenance treatment dose, 1 mg/kg of body weight at a time, 1 to 2 times a day, subcutaneous injection, for 7 to 10 days.

2. Medium-dose cytarabine. Medium-dose cytarabine refers to a dose of cytarabine based on a body surface area of ​​0.5 to 1.0g/m2. Generally, intravenous infusion is required for 1 to 3 hours, twice a day, with 2 to 6 days as a course of treatment. High-dose cytarabine is a dose based on a body surface area of ​​1 to 3g/m2. The intravenous infusion and course of treatment are the same as the medium-dose regimen.

Adverse reactions:
Myelosuppression, nausea, vomiting, liver and kidney damage, oral inflammation or ulcers, thrombophlebitis, fever, occasional abdominal pain, lack of appetite, gastrointestinal bleeding, sepsis, cellulitis at the injection site, pneumonia, neuritis or nerve damage, rash, freckles, skin and mucous membrane bleeding, chest pain, joint pain, sore throat.

Contraindications:
Patients with existing drug-induced bone marrow suppression.

Notes:
1. Cytarabine can only be used under the guidance of doctors experienced in cytotoxic drugs.
2. Patients receiving cytarabine treatment may develop secondary hyperuricemia due to rapid disintegration of tumor cells; serum uric acid concentration should be monitored.
3. The patient's liver and kidney function should be checked regularly.
4. People with poor liver function should use the drug with caution and reduce the dosage, because the liver is an important detoxification organ of the drug.
5. Patients who have been treated with L-asparaginase in the past have been reported to have acute pancreatitis after taking cytarabine.
6. Patients treated with high-dose cytarabine should be observed for neurotoxicity, because changes in the dosage regimen need to avoid irreversible neuropathy.

Medicine for pregnant women and lactating women
For pregnant women, it belongs to category D. Cytarabine is suspected of causing or will cause an increase in the incidence of fetal malformations or irreversible damage. It can also cause adverse pharmacological effects. It is unknown whether cytarabine is excreted in breast milk, and women receiving cytarabine are advised not to breastfeed.

Pediatric Medication
The dose should be adjusted based on factors such as the child's age, weight or body surface area.

Storage:
Cytarabine injection should be stored in the dark below 25°C.

Mechanism of action:
After fluorouracil is enzymatically converted into 5-fluorouracil deoxynucleoside in the body, it forms a covalent bond with the active center of thymidine synthase, inhibiting the activity of the enzyme and causing thymus The production of pyrimidine nucleosides is reduced, resulting in the obstruction of DNA biosynthesis; in addition, it can be converted into fluorouracil triphosphate and incorporated into RNA in the form of pseudo-metabolites, thus interfering with the normal physiological functions of RNA and affecting protein biosynthesis. In recent years, studies have found that the active metabolites of this product, 5-fluorouracil deoxynucleoside and methylenetetrahydrofolate, can form a triple complex with thymidine synthase, preventing the activity of thymidine synthase, thereby inhibiting DNA synthesis. Fluorouracil has a significant killing effect on proliferating cells, especially cells in the S phase. However, it can also delay the transition of cells in the Gl phase to the S phase, resulting in a self-limiting phenomenon.

Efficacy and safety:
Experimental results show
(1) The median complete remission period is 13.5 (3-167) months, the median DFS is 17.5 (3-167) months, and the median overall survival rate (OS) is 22.5 (7-169) months.
(2) The 3-year and 5-year DFS are 55% and 51% respectively, and the 3-year and 5-year 0S are 68% and 54% respectively.
(3) Bone marrow suppression is more obvious, and non-hematopoietic system side effects are mild, which are improved after taking corresponding auxiliary measures. Conclusion HDAr a-C is used for post-remission consolidation treatment of AML, which is expected to shorten the chemotherapy time, increase the disease-free survival rate, and improve the quality of life, and patients can tolerate the adverse reactions that occur during treatment. HDAr a-C is safe and effective for consolidation therapy after remission of AML.