
Empirical pharmacokinetics 33
FIGURE 2.4: The plasma profile after single dose and in steady state after
last dose, for bolus dose administrations
2.5 One compartment drugs with capacity limited elim-
ination
In this section we will have a closer look at one-compartmental drugs, i.e.,
drugs that do not have a distribution phase. For such drugs there is only one
volume, V , and equation 2.2 takes the form
VC
(t)=a(t) − CL(t)C(t).
If, in addition, clearance is constant, and we give a bolus dose D,weget
C(t)=
D
V
e
−CLt/V
,
and for a general administration we have the formula
C(t)=V
−1
t
0
e
−CL(t−s)/V
a(s) ds.