[Pharmacokinetics of 5-fluorouracil in erythrocytes following i.v. administration]

The in vivo binding of the antineoplastic agent 5-fluorouracil (1) to erythrocytes in the whole blood of patients was investigated. The vascular availability of 1 is influenced by erythrocytes at 38.6 +/- 7.2% (calculated as AUC0-60-values), the coefficient of partition is 0.65 +/- 0.18. In comparison with serum, the volume of distribution and the total clearance are elevated by the erythrocytes, the half-lives of the compartment distribution and of the terminal elimination are not influenced.