title: [Plasma concentration of cytosine arabinoside (Ara-C) in the elderly patients with hematological malignancy treated by Ara-C or cytarabine ocfosfate (SPAC)].
abstract: Plasma concentration of cytosine arabinoside (Ara-C) was determined in elderly patients with myelodysplastic syndromes or acute myelocytic leukemia who were treated with subcutaneous injection of Ara-C (Ara-C s.c.; 10 mg/m2/12 hr, 14-21 days), continuous drip infusion of Ara-C (Ara-C d.i.v.; 20 mg/m2/day, 24 hr 14 days) and/or oral administration of cytarabine ocfosfate (SPAC) (SPAC p.o.; 100 mg-300 mg/body/day, 14 days) by radioimmunoassay. In the Ara-C s.c. patients, the peak plasma level (Cmax) of Ara-C was 103 ng/ml and the time to reach Cmax was 15 min. The elimination half-like (t1/2) was 25 min and no accumulation was detected after 14 days of consecutive Ara-C s.c. administrations. In the SPAC p.o. patients, Cmax of Ara-C was 3-8 ng/ml and it took 3-5 days to reach Cmax. The plasma concentration level of Ara-C remains almost at the Cmax level during the SPAC p.o. administration and it remained higher than 0.32 ng/ml for as long as 15 days after the end of administration. In a Ara-C d.i.v. patient, plasma level of Ara-C was detected 4-7 ng/ml during the administration (day 7 through day 14). In all patients bone marrow suppression was observed after chemotherapy regardless of regimen, and there was no significant difference between nadir peripheral cell blood counts of Ara-C s.c. patients and SPAC p.o. patients.
authors.affiliation: Department of Hematology, Tokyo Metropolitan Geriatric Hospital.
authors.forename: H
authors.initials: H
authors.lastname: Tsutsumi
authors.forename: T
authors.initials: T
authors.lastname: Kumakawa
authors.forename: M
authors.initials: M
authors.lastname: Hirai
authors.forename: M
authors.initials: M
authors.lastname: Kikukawa
authors.forename: Y
authors.initials: Y
authors.lastname: Arie
authors.forename: M
authors.initials: M
authors.lastname: Mori
authors.forename: H
authors.initials: H
authors.lastname: Kodo
authors.forename: N
authors.initials: N
authors.lastname: Nakamura
authors.forename: Y
authors.initials: Y
authors.lastname: Murai
authors.forename: R
authors.initials: R
authors.lastname: Mizutani
mesh_terms: D000284:Administration, Oral; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D001088:Arabinonucleotides / Q000008:administration & dosage / Q000493:pharmacokinetics*; D003561:Cytarabine / Q000008:administration & dosage / Q000493:pharmacokinetics*; D003568:Cytidine Monophosphate / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D007279:Injections, Subcutaneous; D015470:Leukemia, Myeloid, Acute / Q000097:blood / Q000188:drug therapy*; D008297:Male; D009190:Myelodysplastic Syndromes / Q000097:blood / Q000188:drug therapy*
chemical_list: D000970:Antineoplastic Agents; D001088:Arabinonucleotides; D003561:Cytarabine; C061162:1-arabinofuranosylcytosine-5'-stearylphosphate; D003568:Cytidine Monophosphate