| Camptothecin anticancer drugs |
Camptothecin anticancer drugs are alkaloids or derivatives of them after the structure transformation raised from deciduous plant Davidia involucrata Camptotheca acuminate seed or root bark. Clinical application of them mainly includes camptothecin,hydroxycamptothecin, topotecan and irinotecan.
Topotecan is a water-soluble semi-synthetic derivative of camptothecin,it is a topoisomerase I inhibitor, inhibiting DNA single strand DNA scission reconnect to damage DNA, its cytotoxicity occurs in cancer cell division S phase, it is an s phase cell cycle specific drug . In vivo it is a two-compartment model,it can be quickly distributed to the liver, kidneys and other parts , of a single intravenous infusion 1.5mg/m2 every 30 minutes , t1/2αis 4.1 to 8.1 minutes, plasma protein binding rate is 6.6%~21.3%,it can go into the cerebrospinal fluid. Most of it is excreted by the kidneys, a small part of it is excreted by the bile, within 12 hours, 90% of it is excreted.Clearance rate of renal dysfunction decreases.it is clinically used for the treatment of small cell lung cancer (SCLC), and advanced ovarian cancer, because it can penetrate the blood-brain barrier ,it has a certain effect on the central nervous system cancer and brain metastases. Usage: every single drug dose 1.2mg/m2 intravenous infusion once a day, once every 5 days, 21 days is 1 cycle, there is the need to reduce the dose when in combination with other anticancer drugs. The main adverse events are hematologic toxicity, white blood cells, platelets and hemoglobin decrease; non-hematologic toxicity adverse events are loss of appetite, nausea, vomiting, hair loss, stomatitis, diarrhea, headache, fever, constipation, transient elevated transaminase; occasionally breathing difficulties, hematuria, andelectrocardiogram abnormalities.
Severe bone marrow suppression are hanged. Monitor the blood and adjust the dose in accordance with changes in blood during the treatment , if necessary, granulocyte colony stimulating factor (G-CSF), and transfusion of blood components may be given .
The above information is edited by the chemicalbook of Tian Ye. |
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