Introduction To Pharmacokinetics

Oral Dosing - Residuals 2/2

A patient is given a 500 mg dose of a drug via a single oral dose.

F = 0.45 t1/2 = 1.5 hours k = 0.462 h-1
AUC = 19.328 mgxh/L CL = 5.174 L/h

What is the value of C*-C at the 1 hour time point? (Answer to one decimal place).

C*-C at 1 hour is: mg/L

Time (h)	Plasma Drug Concentration (mg/L)	C* (mg/L)	C*-C (mg/L)
0	0	8.2
0.5	2.5	6.6	4.1
1	3.2	5.4
1.5	3.1	4.2
2	2.8	3.3
3	2.0	2.1
4	1.3	1.3
5	0.8	0.8
6	0.5	0.5
7	0.3	0.3
8	0.2	0.2

Time (h)	Plasma Drug Concentration (mg/L)	C* (mg/L)	C*-C (mg/L)
0	0	8.2
0.5	2.5	6.6	4.1
1	3.2	5.4
1.5	3.1	4.2
2	2.8	3.3
3	2.0	2.1
4	1.3	1.3
5	0.8	0.8
6	0.5	0.5
7	0.3	0.3
8	0.2	0.2

Time (h)	Plasma Drug Concentration (mg/L)	C* (mg/L)	C*-C (mg/L)
0	0	8.2
0.5	2.5	6.6	4.1
1	3.2	5.4
1.5	3.1	4.2
2	2.8	3.3
3	2.0	2.1
4	1.3	1.3
5	0.8	0.8
6	0.5	0.5
7	0.3	0.3
8	0.2	0.2

Time (h)	Plasma Drug Concentration (mg/L)	C* (mg/L)	C*-C (mg/L)
0	0	8.2
0.5	2.5	6.6	4.1
1	3.2	5.4
1.5	3.1	4.2
2	2.8	3.3
3	2.0	2.1
4	1.3	1.3
5	0.8	0.8
6	0.5	0.5
7	0.3	0.3
8	0.2	0.2