Pharmacological study of modified intermediate-dose cytarabine therapy in patients with acute myeloid leukemia
Sutoh, H.; Yamauchi, T.; Gotoh, N.; Sugiyama, M.; Ueda, T.
Anticancer Research 23(6d): 5037-5042
2003
ISSN/ISBN: 0250-7005 PMID: 14981964 Document Number: 561996
Instead of the original intermediate dose (0.5 g/m2), a modified intermediate-dose 1-beta-D-arabinofuranosylcytosine (ara-C) therapy (1 g/m2, 1-h intravenous infusion) was pharmacologically studied in 11 leukemic patients. The concentrations of ara-C and its inactive metabolite, 1-beta-D-arabinofuranosyluracil (ara-U) in the plasma, urine and cerebrospinal fluid were determined using high performance liquid chromatography. The plasma ara-C reached a peak (61.2 +/- 52.7 microM) that far surpassed the saturating level for intracellular activation of the drug. The plasma ara-U reached its peak (139.8 +/- 40.0 microM) and was maintained with a half-life of 277 +/- 76 min. About 60% of the administered drug was recovered, mainly as ara-U in urine within 12 h. In contrast to the original intermediate dose, the therapeutic ara-C levels (above 0.4 microM) persisted in the central nervous system. The therapy salvaged one relapsed leukemia patient with central nervous system involvement. Modified intermediate-dose ara-C provides a sufficient plasma ara-C level with a concomitant therapeutic concentration in the cerebrospinal fluid.