4-Amino-1-pentofuranosyl-2(1H)-pyrimidinone

DescriptionCytarabine (147-94-4) is a nucleoside analog that interferes with DNA synthesis and transcription, particularly in tumor cells.1,2 Cellular enzymes convert it to its nucleotide form, Ara-CTP, which disrupts DNA and RNA synthesis when polymerases attempt to incorporate it.3,4 For the same reasons, it is also employed as an antiviral.5 It inhibits proliferation of a variety of leukemic cell lines (IC50s 16-72 nM), but is used primarily against acute myeloid leukemia (AML).6

UsesUsed as an antineoplastic and antiviral. A selective inhibitro of DNA synthesis. Does not inhibit RNA synthesis

Usesantineoplastic, antiviral, antimetabolite

UsesCytarabine USP (Cytosar)is used to treat Acute granulocytic leukemia (adults); acute lymphocytic leukemia (children); Hodgkin’s disease

General DescriptionCytarabine is a pyrimidine nucleoside drug that is related toidoxuridine. This agent is primarily used as an anticanceragent for Burkitt lymphoma and myeloid and lymphaticleukemias. Cytarabine blocks the cellular utilization of deoxycytidine,hence inhibiting the replication of viral DNA.Before it becomes active, the drug is converted to monophosphates,diphosphates, and triphosphates, which block DNApolymerase and the C-2 reductase that converts cytidinediphosphate into the deoxy derivative. The antiviral use of cytarabine is in the treatment of herpeszoster (shingles), herpetic keratitis, and viral infectionsthat resist idoxuridine. Cytarabine is usually administeredtopically. Toxicity occurs on bone marrow, the gastrointestinal(GI) tract, and the kidneys.

General DescriptionThe drug is available in 100-, 500-, 1,000-, and 2,000-mgmultidose vials for IV use. Cytarabine is used in the treatmentof acute myelogenous leukemia and CML. This drugis a deoxycytidine analog originally isolated from thesponge Cryptothethya crypta. It is active following intracellularactivation to the nucleotide metabolite ara-CTP. Theresulting ara-CTP is incorporated into DNA resulting inchain termination and inhibition of DNA synthesis andfunction. Resistance can occur because of decreased activationor transport and increased catabolic breakdown.Metabolic breakdown within the GI tract leads to poorbioavailability. The drug distributes rapidly into tissues andtotal body water with cerebrospinal fluid (CSF) levelsreaching 20% to 40% of those in plasma. Cytidine deaminaseis the primary catabolic enzyme involved in the inactivationof cytarabine. Drug interactions include antagonismof the effects of gentamicin, decreasing the oral bioavailabilityof digoxin, as well as enhancing the cytotoxicity ofvarious alkylating agents, cisplatin, and ionizing radiation.Toxicities include myelosuppression, leukopenia andthrombocytopenia, nausea and vomiting anorexia, diarrhea,and mucositis. Neurotoxicity is usually expressed as ataxia,lethargy, and confusion. An allergic reaction often describedin pediatric patients includes fever, myalgia, malaise, bonepain, skin rash, conjunctivitis, and chest pain.Pretreatment with methotrexate enhances the formation ofara-CTP metabolites resulting in enhanced cytotoxicity.