(19S)-8-[(dimethylamino)methyl]-19-ethyl-7,19-dihydroxy-17-oxa-3,13-diazapentacyclo[11.8.0.02,11.04,9.015,20]henicosa-1(21),2,4(9),5,7,10,15(20)-heptaene-14,18-dione;hydron;chloride

용도A DNA topoisomerase I inhibitor; semisynthetic analog of Camptothecin. Antineoplastic. Topotecan hydrochloride is a chemotherapy agent that is a topoisomerase 1 inhibitor.

일반 설명Topotecan is supplied in 4-mg vials and administered IV forthe treatment of ovarian cancer, cervical cancer, and smallcell lung cancer in those patients who did not respond tofirst-line therapy. Following IV administration, the drug iswidely distributed with 10% to 35% of the agent bound toplasma proteins. There is evidence that the agent may crossthe blood-brain barrier to some extent. In plasma, an equilibriumis established between the lactone and the less activehydroxy acid with 20% of the drug present as the lactone 1hour after the infusion is complete. In contrast to irinotecan,both the lactone and the hydroxy acid bind equally well tohuman serum albumin. N-Demethylation of the tertiaryamine to give the secondary amine is mediated by CYP3A4and represents a minor route of metabolism. Glucuronidationof the parent and the phase I metabolites also occurs to a limited(10%) extent.Elimination occurs primarily in theurine, with 30% of the dose being recovered as unchangeddrug. The terminal elimination half-life is 2 to 3 hours. Themajor toxicity seen for topotecan is dose-limiting myelosuppression.Nausea and vomiting are seen in most (70%–80%)patients, along with diarrhea and abdominal pain. Other toxicitiesinclude headache myalgias, alopecia and elevation ofserum transaminases, alkaline phosphatases, and bilirubin.Microscopic hematuria (blood in the urine) may also be seen.