Pharmacokinetics of fluorouracil by intravenous or intraarterial injection

High-performance liquid chromatographic (HPLC) analysis of fluorouracil (5-FU) content of the blood and colon of rabbits is described. There was no marked difference in the plasma 5-FU level and blood concentration time curve following intravenous (I.V.) (ear vein) or intraarterial (I.A.) (inferior mesenteric artery) injection of 5-FU 15 mg/kg. However, the distribution of 5-FU in the colon after I.A. administration was quite different that after I.V. administration. At 10, 20 and 30 minutes, the 5-FU content in the colon was shown to be 31-, 17- and 14-fold higher with I.A. than with I.V.. Colonic tissue AUC_0–480 min. was 2453 and 690 min/mg/ml respectively (p<0.05). It is suggested that to inject 5-FU into selected arteries to treat advanced colorectal cancer may be more useful than I.V. administration.