[Comparison of gastrointestinal toxicity of 5-FU derivatives].
Gastrointestinal toxicities of tegafur (FT) and doxifluridine (DFUR) were compared using mouse intestinal enzymes as the marker. Enzyme activities were decreased during repeated administration of these 5-FU derivatives. When the drugs were administrated once a day, the decrease of enzyme activities were almost equal, but when administrated twice a day. DFUR showed greater decrease. Pharmacokinetical analysis revealed faster catabolism of DFUR than FT. In vitro 5-FU formation by GI extract was much higher from DFUR than FT. These data show a good agreement with the fact that the incidence of diarrhea is much higher in DFUR than FT.
Imamura
I
I
Dept. of Pharmacology II, Faculty of Medicine, Osaka University.
Yabumoto
M
M
Fukui
H
H
Wada
H
H
Takechi
T
T
Takeda
S
S
Yamada
Y
Y
D000284:Administration, Oral; D006631:Amine Oxidase (Copper-Containing) / Q000378:metabolism; D000818:Animals; D000970:Antineoplastic Agents / Q000633:toxicity*; D004064:Digestive System / Q000187:drug effects* / Q000201:enzymology; D005467:Floxuridine / Q000633:toxicity*; D007420:Intestine, Large / Q000187:drug effects; D007421:Intestine, Small / Q000187:drug effects; D008297:Male; D051379:Mice; D005641:Tegafur / Q000633:toxicity*
D000970:Antineoplastic Agents; D005467:Floxuridine; D005641:Tegafur; D006631:Amine Oxidase (Copper-Containing); C025034:doxifluridine