A vo
A eq
B
A
Th fo
co re
B
in
2.1.2 Li
pСarma proport
fact tСa parame
one sТm tСerape
Тnvolved order k
A The one-com olume
V
1
, whi A
1
, which is eq qual to the plas
B Semi-logarith
A The two-com
he volumes V
or the central ompartment is
edistribution R
B The two-co
travenous adm
inear and N
Most of acokТnetТcs,
Тonal wТtС t at all proce
eters are co NonlТnearТty
mple fТrst-o eutТc drug c
d Тn ADME kТnetТcs. S
Figure 2. 1
mpartment mo ich is equals to
qual to the am sma concentra
hmic plot of Cp
Figure 2. 2
mpartment mod V
, amounts A
and periphe equal to the p
R are k
12
and k
2
ompartment m ministration.
Non Linear
drugs us tСe plasm
Сe concent esses Тn d
nstant and y Тn tСe pСa
order kТnetТc concentratТo
. In saturat Saturable
The one-com
odel consists o o the drugs vo
mount of drug ation
Cp. The
p against time
2 The two-com
del consists of , and concent
eral compartm plasma conce
21
respectively models semi-
r Pharmaco
sed clТnТca ma concen
tratТon follo drug nature
do not cСan armacokТne
cs. NonlТne ons are СТg
tТon, tСe pr metabolТsm
5
mpartment m
only of a cent olume of distrib
in the body A
first-order rate obtained after
mpartment m
f the central c ration
C in e
ment respectiv ntration Cp.
y. The first-orde logarithmic p
okinetics
ally follow ntratТon of
ows fТst-ord e are fТrst
nge wТtС tСe etТcs arТses
earТty Тn pС gС enougС t
rocess take m also ref
odel Rosenb
tral compartme bution
Vd ; th
Ab ; and the d
e constant for e intravenous a
odel Rosenb
compartment a ach compartm
vely. Drug co The rate cons
er rate constan plot of Cp ag
w lТnear p a drug Т
er kТnetТcs order and
e dose Ros wСen a pro
СarmacokТne to saturate
s place at ferred as
baum, 2011
ent. It is chara e amount of dr
drug concentra elimination
E dministration.
baum, 2011
and peripheral ment are qualifi
oncentration in stant for distrib
nt for eliminatio gainst time o
pСarmacok Тs cСanged
. TСe term or tСat tСe
senbaum, 2 ocess Тn AD
etТcs arТses an enzym
a constant capacТty-lТ
acterised by a rug it contains
ation, which is is
k .
compartment. ied by
1 and
2 n the central
bution D
and on
E is
k
10
. obtained after
ТnetТcs. In d exponen
lТnear Тs b e pСarmaco
2011. DME Сas m
s mostly w e or otСer
rate follow mТted met
a s
s
2 r
n lТnear tТally or
ased on okТnetТcs
ore tСan wСen tСe
proteТns ws zero-
abolТsm,
6 bТotransformatТon or elТmТnatТon Тs tСe most example of nonlТnear pСarmacokТnetТc observed
clТnТcally. PСenytoТn Тs an example of drug tСat sСows tСТs pСarmacokТnetТcs Rosenbaum, 2011.
Figure 2. 3 The three-compartment model Rosenbaum, 2011
A
The two-compartment model consists of the central, peripheral and deep tissue compartment. The volumes
V , amounts
A , and concentration
C in each compartment are qualified by
1 ,
2 and 3 for the central, peripheral and deep tissue compartment respectively. Drug concentration in the
central compartment is equal to the plasma concentration Cp. The rate constant for distribution D
and redistribution R
to the peripheral compartment are k
12
and k
21
respectively. The rate constant for distribution
D and redistribution
R to the deep tissue compartment
are k
13
and k
31
respectively The first-order rate constant for elimination E
is k
10
. B
The three-compartment models semi-logarithmic plot of Cp against time obtained after intravenous administration of.
2.2 Test Drugs