Abstract
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.
Footnotes
- Received November 4, 1974.
- Copyright © 1975 by The American Society for Pharmacology and Experimental Therapeutics
DMD articles become freely available 12 months after publication, and remain freely available for 5 years.Non-open access articles that fall outside this five year window are available only to institutional subscribers and current ASPET members, or through the article purchase feature at the bottom of the page.
|