Pharmacokinetics of ara-C and ara-U in plasma and CSF after high-dose administration of cytosine arabinoside.
Cytosine arabinoside (ara-C) and uracil arabinoside (ara-U) levels were measured in the plasma, cerebrospinal fluid (CSF), and urine of 10 patients exhibiting primary central nervous system lymphoma who received 31 infusions of high-dose ara-C (3 g/m2) as part of their treatment regimen. Peak plasma and CSF ara-C levels were 10.8 and 1.5 micrograms/ml, respectively. Ara-C was cleared more rapidly from plasma than from CSF. Ara-U appeared rapidly in both plasma and CSF, reaching a peak that was 10 times higher than the corresponding ara-C concentration (104 and 11.2 micrograms/ml, respectively). Only 4%-6% of the dose was excreted unchanged in the urine, but 63%-73% of it appeared as ara-U within the first 24 h. The presence of leptomeningeal lymphoma did not affect the CSF level of ara-C or ara-U.
DeAngelis
L M
LM
Department of Neurology, Memorial Sloan-Kettering Cancer Center, New York, New York 10021.
Kreis
W
W
Chan
K
K
Dantis
E
E
Akerman
S
S
D001086:Arabinofuranosyluracil / Q000008:administration & dosage / Q000493:pharmacokinetics*; D016543:Central Nervous System Neoplasms / Q000188:drug therapy* / Q000532:radiotherapy; D003131:Combined Modality Therapy; D003561:Cytarabine / Q000008:administration & dosage / Q000493:pharmacokinetics*; D005260:Female; D006207:Half-Life; D006801:Humans; D008223:Lymphoma / Q000188:drug therapy* / Q000532:radiotherapy; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged
D003561:Cytarabine; D001086:Arabinofuranosyluracil