TY - JOUR T1 - THE DISPOSITION OF FTORAFUR IN RATS AFTER INTRAVENOUS ADMINISTRATION JF - Drug Metabolism and Disposition JO - Drug Metab Dispos SP - 303 LP - 308 VL - 3 IS - 4 AU - ARTHUR M. COHEN Y1 - 1975/07/01 UR - http://dmd.aspetjournals.org/content/3/4/303.abstract N2 - The excretion, distribution, and metabolism of ftorafur was studied in rats following a single intravenous injection of radioactively labeled drug. Approximately 55% of the administered radioactivity was excreted as 14CO2, while 23% was eliminated via the urinary route in 24 hr. Less than 2% was excreted in the feces. The major excretory product found in the urine was unmetabolized ftorafur. However, the proportions of radioactively labeled metabolites such as 5-fluorouracil and urea increased with time after injection. The half-life of ftorafur in plasma was estimated to be approximately 5 hr. The drug was fairly evenly distributed to liver, small intestine, spleen, kidney, and brain. Highest initial concentrations were found in the liver, which also retained more drug for a longer period than the other tissues. The liver was also found to contain the highest initial proportions of 5-fluorouracil and its metabolites. The results obtained are consistent with the suggestion that ftorafur may be a depot form of 5-fluorouracil and that the liver may be the primary site at which the latter drug is released in vivo. Copyright © 1975 by The American Society for Pharmacology and Experimental Therapeutics ER -