Table 3

Pharmacokinetic parameters of tegafur and 5-FU in humans

Tegafur (2500 μmol, b.i.d.)
 Fa 1 Anttila et al., 1983
 k a 0.1/min−1a
 K p 1 (assumed)
 fb 0.6fb = fu/RB, RB = 1 was assumed. Benvenuto et al., 1978
 CLint,1 24.8 ml/min3-a CLint for non-5-FU pathway
 CLint,2 5.2 ml/min3-a CLint for 5-FU pathway
 Vsys 12,500 ml3-a
5-FU
 K p 1 (assumed)
 fb 0.9fb = fu/RB, RB = 1 was assumed. Goodman and Gilman, 1996
 CLtot 1070 ml/min Heggie et al., 1987
 CLh 856 ml/minCLtot × 0.8 Diasio and Harris, 1989
 CLint 2030 ml/minaccording to well-stirred model
 K m 23 μM Yamazaki et al., 1996
 V max 46,700 nmol/mincalculated by CLint × K m
 CLr 214 ml/minCLtot × 0.2 Diasio and Harris, 1989
 V sys 13,100 ml Heggie et al., 1987
Physiological parameters
 Q1610 ml/min
 Vliver 2800 ml
 Vpv 70 ml
 E0 0.24 nmol/g liverPresent study (see Fig. 3)
 k deg 0.00024/min−1b Yan et al., 1997

  • ↵3-a Calculated by equations 13-16 to fit the reported blood concentration (Nakajima et al., 1980).

  • 3-b Calculated from the recovery pattern of 5-FU-reducing activity of DPD in peripheral blood mononuclear cells after administration of sorivudine.